bitbake: toaster: Clean up and convert to rest api project edit and get calls

bitbake: toaster: Clean up and convert to rest api project edit and get calls

Convert the project xhr calls into proper rest api and port the client
side calls to use the new API. Fix all the pyflakes identified issues
and clean up unused fields.

Also remove the api and client side code for changing release on the fly
as this is no longer supported.

[YOCTO #9519]

(Bitbake rev: 8b01767d6e787cdb09789116ebf57dfb70f521bc)

Signed-off-by: Michael Wood <michael.g.wood@intel.com>
Signed-off-by: Ed Bartosh <ed.bartosh@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>