Add CRUD support for Projects API

[hs26gill]

Description

A new Projects API is added to allow users to organize and centrally manage their workspaces at scale.

Testing plan

To run the integration test:

ENABLE_BETA=1 go test -run TestProjectsRead  -v ./... -tags=integration

ENABLE_BETA=1 go test -run TestProjectsCreate  -v ./... -tags=integration

ENABLE_BETA=1 go test -run TestProjectsUpdate -v ./... -tags=integration

ENABLE_BETA=1 go test -run TestProjectsDelete  -v ./... -tags=integration

ENABLE_BETA=1 go test -run TestProjectsList  -v ./... -tags=integration

---

• To see the specific tasks where the Asana app for GitHub is being used, see below:
  • https://app.asana.com/0/0/1203185457641102
  • https://app.asana.com/0/0/1203185457641104
  • https://app.asana.com/0/0/1203185457641103

[jbonhag]

Nicely done -- a couple of nitpick/naming-related things but it seems to be in good shape!

[sebasslash]

Moving in the right direction 🕺 Some comments down below 😄

[brandonc]

All this looks great. My one bit of blocking feedback is that all the new go docs need to be clearly labeled as beta, and the CHANGELOG should make it clear that the features are not generally available and subject to change.

Ex:

type Projects interface
    // List all projects in the given organization
    // **Note: This field is still in BETA and subject to change.**
    List(ctx...)
...
}

See the Adding API Changes that are Not Generally Available section of CONTRIBUTING.md for details.

Changes addressed

[github-actions]

Reminder to the contributor that merged this PR: if your changes have added important functionality or fixed a relevant bug, open a follow-up PR to update CHANGELOG.md with a note on your changes.