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This portal has been superseded by the Met Data Portal - PCDS, which is an app independent of PDP.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 pacificclimate/pdp_util#47

TODO:

• Remove BC Station Data Portal frontend code (JS).
• 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• All other PyDAP code has been replaced by usage of THREDDS+ORCA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.