Add entity update

[lognaturel]

https://docs.getodk.org/central-api-entity-management/#updating-an-entity

Proposed parameters:

• dataset name (required)
• entity uuid (required)
• one of boolean force or integer base_version (one required)
• label (string, optional)
• data (dictionary, optional)

I thought about defaulting force to True but that feels dangerous to me. I think it's best for a user to have to make an explicit decision around that.

I also thought about combining force and base_version but can't come up with anything that feels natural.