Code and location from children

[konradweiss]

This PR allows the setting of a node's code and location region as the code and location of its children.
Sometimes, when we translate a parent node in the language-specific AST with its children into the CPG AST, we have to set a specific intermediate Node between that has no language-specific AST that can give it a proper code and location.

This PR provides the function codeAndLocationFromChildren(frontend: LanguageFrontend<S, *>, parentNode: S) that is purely optional and can be used in language frontends to cover the use-case mentioned above and set the region of the node to the start and end region of its children. The code is then extracted from the language-specific AST parent using the newly determined location region.

The function modifies the base node, meaning it should be used after construction:
newBlock(...).codecodeAndLocationFromChildren()
or before returning the node if the children are processed and returned after construction:
return block..codecodeAndLocationFromChildren()

[konradweiss]

The quality gate fails because I cannot test it without using the function in a frontend, which I will add and then test in #1388. And unfortunately cannot add with the Fluent Node DSL as I need access to rawNodes and a valid frontend unless I heavily restructure the code just to make it testable and jump through some more hoops.

[sonarcloud]

Quality Gate failed

Failed conditions

11.6% Coverage on New Code (required ≥ 75%)

See analysis details on SonarCloud