splash page: add "registered users" section; switch to volume 9

Fixes #2300
Add "get authorized" link to profile menu
Stay in registration after password reset
Always show volume splash when unlocked

See #2299
Fixup to last: retrieve splash volume data
Don't fall over if can't load splash volume
Send id to investigator agreement generator

Requires commit 30501bafe00275d2aeb33afcabba73df839b2141 on www
Remove databrary-only access level

See #2302
change access page text down to two options
change header text on splash page

databrary investigators should change to authorized investigators now that we are including the list of other registered, non-authorized users