Integrate blobs with platform

Things that have to be done in platform:

• configuration of blobs path (discuss /srv creation by debian package). #8948 (closed)
• configuration of quota limit (per user) #8880, #8833, #4799, webapp#5589
• backups and monitoring of blobs path. platform#8858 (closed)
• configuration of incoming api access token (in soledad and mx) leap_mx#8664 (closed) platform#8857
• configure new soledad entrypoints platform#8854

Things needed from client devs:

• e2e tests #8941 (closed)
• add documentation: #8953 (closed)

Debian package should:

• create the default blobs path.
• maybe show a warning on upgrade with info on changes on configuration.

Update: updated the items above, adding the auth and migration discussion from kali's comments below.

Update: added issue number for default blobs path (#8948 (closed))

Update: add issue number for documentation improvement (#8953 (closed))