Fix code generation for methods with default arguments

[HugoX104447]

Context

This pull request addresses an issue in the code generation process for methods with default arguments. The current implementation does not correctly handle default values for parameters, leading to compilation errors.
These changes ensure that the code generator correctly handles default values for a wide range of parameter types.

Changes Made

• Refactored GetParametersWithTypesAndModifiers Method:

  • Added a wrapInArg parameter to indicate whether the default values should be wrapped in Arg<T>.

• Added GetDefaultValueForType Method:

  • This method handles various primitive types, tuples, and other value types.
  • It returns the appropriate default value based on the type and the explicit default value.

• Added GetEnumDefaultValueString and FindEnumMember Methods:

  • These methods introduce special handling for enums to convert raw values to their corresponding enum members.
  • GetEnumDefaultValueString uses a switch expression to handle different enum underlying types.
  • FindEnumMember uses the Roslyn Semantic Model to iterate over the enum members (fields) and check their constant values, comparing them to the parameters ExplicitDefaultValue.

• Updated Unit Tests:

  • Added a new test class DefaultArgTests to validate the behavior of the refactored code.
  • Included tests for methods with various default argument types, such as primitives, nullables, strings, enums, and multiple defaults.

[connorivy]

Hey @HugoX104447,

This is a fantastic PR, it is thoroughly tested, and your code is easy to follow. Thanks so much. I merged this in and made a new release, 1.1.0 (with all of you other PRs).

I did end up making one change which was to move the test that you added from the 'MockMe.Tests' project to the 'MockMe.Tests.Overloads' shared project. The difference is that the latter project is run for multiple types of mocks (interfaces, sealed classes, standard classes), so I like to put source gen related tests there.

Let me know if you have any issues with the new version!