Added correct handling of SXI framing according to ASAM MCD-1 (XCP on…

[thats-i-t]

• Added correct handling of SXI framing according to ASAM MCD-1 (XCP on SxI) v1.5.0 (if enabled by user)
• Furthermore in SxI the ESC and SYNC options corrected: ESC_ESC=0x00 ESC_SYNC=0x01 are defined by the standard while ESC and SYNC are configurable

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• [ x ] New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• [ x ] I have read the CONTRIBUTING document.
• [ x ] My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed. (bandit, ruff, flake8 all failed due to already existing issues)