[Core] Bump mouse endpoint packet size to 16 bytes

[KarlK90]

Description

...to accommodate mouse reports with a size of 9 bytes, which happens
when the extended 16 bit movement range is activated by defining
MOUSE_EXTENDED_REPORT and MOUSE_SHARED_EP is NOT set.

Types of Changes

• Core
• Bugfix
• New feature
• Enhancement/optimization
• Keyboard (addition or update)
• Keymap/layout/userspace (addition or update)
• Documentation

Issues Fixed or Closed by This PR

• Miss match in mouse endpoint packetsize when mouse_report_t has MOUSE_EXTENDED_REPORT set

Checklist

• My code follows the code style of this project: C, Python
• I have read the PR Checklist document and have made the appropriate changes.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• I have tested the changes and verified that they work and don't break anything (as well as I can manage).

[sigprof]

Technically this report size check should not be needed, because HID reports are allowed to be larger than the endpoint packet size, and apparently the USB LLD should be able to split large transfers into multiple packets (one complication is when the report size happens to be an integer multiple of the packet size, but smaller than the maximum report size declared in the report descriptor — in that case the device would need to send a zero length packet after the report, and this would need to be done separately from sending the body of report).

[KarlK90]

@sigprof Thanks for the explanation, I wasn't aware of that.

I've reverted all of the changes except the mouse endpoint packet size bump, as there is IMHO some value in not having to send out two packets for the extended mouse reports.