Add a helper function to connect Thing Slots on already-created Things.

[rwb27]

Trying to mock descriptors is painful, but lt.thing_slot is relatively easy to reconnect with a little boilerplate.

This PR adds a helper function so test code can easily connect Things together without a server.

[barecheck]

Barecheck - Code coverage report

Total: 96.86%

Your code coverage diff: 0.00% ▴

Uncovered files and lines

File	Lines
src/labthings_fastapi/testing.py	140, 257

[julianstirling]

I love this. Probably against protocol for it to go in before 0.2 is released?

[rwb27]

It's clearly only touching code in testing so I'd have no problem squeezing it in.

OFM v3 check is only failing because of api_prefix which will be fixed there soon enough.