[Tests] Move to the new test suite of Xcode

[pylapp]

Context

Today we use the old and battle-tested XCTest framework for our unit tests.
These tests are based one Swift classes, implementing XCTestCase ans using all the XCTAssert* test functions.
Due to the increasing amount of tests, it could be interesting to mvoe to the new Swift testing framework annoucned in 2024 and introduced in the WWDC24

Definition of Done

• Check if this new framework can be used beside the old one (use for UI tests)
• Migrate all unit tests on raw tokens
• Migrate all unit tests on semantic tokens
• Migrate other unit tests (for helpers, foundations, etc)
• Update CHANGELOG
• Update wiki
• Update any other documentation mentioning XCTest