Revamp URLs to support other sources

[brianpipa]

Right now we have 2 types of search URLS - overdrive and KU:
http://overreader.com/overdrive/mcplmd,wakegov,dclibrary,alexandria/5535346/favorites?lookfor=e,a
http://overreader.com/kindleunlimited/5535346/favorites

or more generically...
http://overreader.com/overdrive/LIBRARIES/GR_USER/GR_SHELF?lookfor=e,a
http://overreader.com/kindleunlimited/GR_USER/GR_SHELF

but this doesn't support other types of searches. We may want to add in other source (like thestorygraph) and Goodreads group lists.

So, let/s change to something like:
http://overreader.com/SEARCH_TYPE/SOURCE_NAME_TYPE/SOURCE_ID/SHELF
so the above two would become
http://overreader.com/overdrive/mcplmd,wakegov,dclibrary,alexandria/goodreads_user/5535346/favorites?lookfor=e,a
http://overreader.com/kindleunlimited/goodreads_user/5535346/favorites

so for a goodreads group list, goodreads_user becomes goodreads_group
for storygraph it changes to storygraph_user like:
GR group: http://overreader.com/kindleunlimited/goodreads_group/474371/10-challenge-pern
SG user: http://overreader.com/kindleunlimited/storygraph_user/brianpipa/currently-reading

GR group: http://overreader.com/overdrive/mcplmd,wakegov,dclibrary,alexandria/goodreads_group/474371/10-challenge-pern
SG user: http://overreader.com/overdrive/mcplmd,wakegov,dclibrary,alexandria/storygraph_user/brianpipa/currently-reading