(Editing not finished, please wait before responding, etc.)

With dbserv now converging on providing a TAP service, it's time to implement the "generic table browsing" feature that we need in the Portal so that we don't have to implement custom screens for every table.

The "generic browsing" screen should take a TAP endpoint as a parameter (this may come from a configuration parameter of the Portal in LSST's standard usage, or it may come from a "higher level" search facility that interacts with the VO Registry).

Given this parameter, it should use TAP_SCHEMA and/or the .../tables endpoint of the TAP service to obtain a list of tables, and display this list to the user.