make graphRegex simpler

Context

In issue Bug : Advanced node testing with Graph Regex an... (#86 - closed), the problem arises from the syntax of the lambda declaration, which is not intuitive.This modification aims to automatically add the lambda key as a test and eliminate the need to do it in two steps. It also adds the ability to accept True and False as bool in expressions.

Modified files

Add the automatically add the lambda key in :

src/graphRegex/GraphRegex.cpp

Add the True and False :

src/nodeTester/ConditionalLexer.cpp

CI :

unit_tests/graphRegex/Test_GraphRegex.cpp