code-coverage: modify intermediate layer algorithm to improve code coverage

- The intermediate layer uses traces from the plugin and DWARF data
from the binaries to match and create code coverage.
- The regulars expresions that group functions within the DWARF
data had been modified in order to capture more functions in the
binaries that correspond to source code.
- A refactoring including more classes were created to encapsulate
how the algorithm was implemented by the code.

Signed-off-by: Saul Romero <saul.romero@arm.com>