Restructure repository (#26)

* middleware: Restructure external projects integration

* External projects are referred to as `components`
* The components are grouped per category within the `components`
  subdirectory.
* Each component contain a `library` subdir (containing the external
  project)
  and an `integration` subdir (containing additional code to integrate
  the external project).
* The external project used for the BSP is now also located in a
  `library` subdir within the `Bsp` subdir.

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* cmake: Provide components and BSP as part of the FRI

Rather having applications include individual parts of the FRI,
include all of its parts (BSP and components) in the root level
CMakeLists.txt

To build application, point CMake to each application's main
CMakeLists.txt as application should be treated as the root level
CMakeLists.txt. This approach also shows how users who may want to
include the FRI as a dependency to their project can build
applications by treating their applications as the root
level project.

Additionally:
* Raise an error if the minimum CMake version requirement is not met.
* Rename FRI CMake project to match FRI project name.
* Expose Tools/cmake subdir to CMake to find additional modules

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* apps: Do not share configuration files

This allows each application to apply configurations it needs
without changing the behaviour of other applications as was
previously the case since they share configuration files.

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* blinky: Improve CMake support

* Define all CMake variables to be used by the project prior to
  creating the project
* Sort list items alphabetically so they are easier to find
* Add fatal error if minimum CMake version is not used
* Remove unnecessary comments to declutter
* Handle compiler specific configurations in one location
* Move BSP configuration to BSP subdir
* Include only the libraries used by the application

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* apps: Improve Provisioning Python script

* Add type notation
* Wrap long lines
* Clarify variables and function names
* Process CLI arguments with click

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* aws-iot-example: Improve CMake support and organisation

* Define all CMake variables to be used by the project prior to
  creating the project
* Sort list items alphabetically so they are easier to find
* Add fatal error if minimum CMake version is not used
* Remove unnecessary comments to declutter
* Handle compiler specific configurations in one location
* Move BSP configuration to BSP subdir
* Include only the libraries used by the application

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* aws-iot-example: Add FreeRTOS libs integration test app

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* run-script: Fix root path and wrap long string

Improve readability of the string by wrapping it.

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* provisioning: Make provisioning available to all apps that need it

Move the provisioning source code and script to the helpers subdir

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* bsp: Rename `Bsp` subdir to `bsp`

The project is adopting snake case for files
and subdirectories names

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* bsp: Rename CMake script

CMake modules follow the typical naming convention of
VerbWithCamelCase.

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* docs: Rename `Docs` subdir following snake_case

The project is adopting snake case for files and subdirectories names

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* apps: Rename `Projects` subdir to `applications`

Improves the description of the content of the subdir.

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* tools: Rename `Tools` subdir following snake_case

The project is adopting snake case for files and subdirectories names

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* provisioning: Rename CMake script

CMake modules follow the typical naming convention of
VerbWithCamelCase.

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* aws-iot-example: Rename files and subdirs following snake_case

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* blinky: Rename files and subdirs following snake_case

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* docs: Add subdirectory description to README

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* ci: Move tools to `tools` subdir

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* tests: Move conftest.py to `tools/tests/`

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* docs: Add project organisation document

The document describes the various subdirectories
and conventions used througout this project.

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

* ci: Add known words to spellchecker

The added words are valid and therefore added
to the spellchecker dictionary.

Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>

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Signed-off-by: Hugues Kamba-Mpiana <hugues.kambampiana@arm.com>