Add CodeSpell to Actions, and fix some spellings

[julianstirling]

Spell checking in CI, these changes are needed to make it pass.

The only code changes are to some test names as it is spell checking snake_case and doesn't like cant but we cant add an apostrophe to a function name.

[barecheck]

Barecheck - Code coverage report

Total: 92.34%

Your code coverage diff: 0.00% ▴

Uncovered files and lines

File	Lines
src/labthings_fastapi/client/in_server.py	120-122, 296
src/labthings_fastapi/dependencies/blocking_portal.py	45-46, 51
src/labthings_fastapi/descriptors/action.py	126, 130, 210-211, 215, 221, 223, 315-316, 319
src/labthings_fastapi/descriptors/property.py	108, 110, 138, 140, 177-178, 343-344
src/labthings_fastapi/example_things/__init__.py	169
src/labthings_fastapi/outputs/blob.py	92, 97, 104, 111, 137, 234, 362, 367-368, 401-402, 407, 448, 567, 643, 750
src/labthings_fastapi/outputs/mjpeg_stream.py	189, 191, 194, 197, 249-251, 260-262, 289-291, 329, 419, 456
src/labthings_fastapi/server/fallback.py	113
src/labthings_fastapi/thing.py	240, 298, 348, 361
src/labthings_fastapi/thing_description/__init__.py	67, 76-77, 158-163, 180-184, 196, 325-326, 333

[rwb27]

All seems good to me, nice to fix my spelling errors at last! I'm hoping if I approve it it won't stop you from being able to add .vscode to the excluded directories - can't remember if extra commits are allowed post-approval.