feat: expose capabilities in MapeoProject and its member api

[achou11]

Closes #239

Exposes capabilities in the following ways:

• adds a $getOwnCapabilities() method to MapeoProject
• adds a capabilities field to the return value of project.$member.getById() and project.$member.getMany()

TODO:

• Feel like some of the tests belong in e2e but not sure if that's blocked on the invites stuff
  • the e2e capabilities tests should ideally be able to use project.$member to retrieve the capabilities. currently relies on Save relevant device info when initially creating/adding a project #289 and updating the MemberApi.invite() implementation
  • the e2e manager invite tests should check that the inviter can retrieve the member's device info using the member api after the invite is accepted
• still wondering what the best way to get your own capabilities for a project is. basically, should there be a project.$getOwnCapabilities() method?
  • Update tests to account for this method

[gmaclennan]

Looks good, I think we can sort out the e2e tests once we have some of the other things in place.

Reviewing this I realized that we need to tweak a couple of other things, which I have opened issues for:

• member.invite() should throw immediately if device does not have capabilities #299
• Default capabilities when no capabilities record exists #298