Remove BC Station Data Portal (PCDS) after Dec 31, 2022

[rod-glover]

This portal has been superseded by the Met Data Portal - PCDS, which is an app independent of PDP. The old portal (in PDP) is scheduled to be made unavailable ~on or shortly after Dec 31, 2022~ as of May 30.

This issue coordinates with https://github.com/pacificclimate/pdp_util/issues/47

TODO:

• [x] Remove BC Station Data Portal frontend code (JS).
• [x] Remove the user and developer frontend documentation for this portal.
• [ ] Remove BC Station Data Portal backend code (Python). We currently have a separate branch of PDP that runs only the PCDS backend. See discussion below.
• [ ] Remove remaining documentation for this portal.

[rod-glover]

It's possible that this issue should be split into "remove frontend (code and documentation)" and "extract PCDS-only to a separate project". The latter of course would include removing the code from this repo. That sounds saner.

UPDATE: Done.

[rod-glover]

We now prefer to merge branch pcds-only into the mainline after:

• BC Station Data Portal has been removed from this project
• All other PyDAP code has been replaced by usage of THREDDS+ORCA

Then we can deploy a pcds-only configuration to serve data to MDP.