Fd 869 add status check to api

[ThomasMeier]

This arises from a discussion with Anton, Jay, Matt, and I about a status endpoint. This arises from discussion about #671 in which the solution is to create a standalone, separate program to determine readiness from facts about the server. This PR is to propose adding a GET /status endpoint to the node with a variety of information the user can find for determining readiness. This helps satisfy some elements that the open api project and other projects want to use, in particular:

1. A GET route to return 200. For now this is good enough singular point for checking liveness.
2. Returns a collection of information to give insight to the user about readiness.

This is based on a sketch so let me know if this needs to go to a different branch or get rebased or moved to a different path, etc., the relevant code is under wsapi/wsapi.go

[stackdump]

TODO:

1. add docs about what each flag means
2. add db syncing flag
3. Ignore mode flag