pfdi-cli: Introduce PFDI-CLI application

Introduce a sample command-line interface (CLI) for PFDI,
providing the following functionalities:

 - Retrieve library and firmware versions
 - Inject errors for testing purposes
 - Display firmware test counts
 - Show Out-of-Reset (OOR) results

This tool facilitates testing and diagnostics of PFDI components.

Signed-off-by: Ziad Elhanafy <ziad.elhanafy@arm.com>
Signed-off-by: Divin Raj <divin.raj@arm.com>