refactor(frontend): responsive grants and show errors

* install: package for Debian 11 (Bullseye)

* install: foreign key for domain_ports and indexes for newest mariadb

concurrent start and open_iptables could mess with iptables

issue #1488

fixes issue #1576

refactor: check client connection status

* checks on any display type
* checks on port connected

issue #1569

fix: sets start_limit to 0 to admins

* fix(install); wait for grants creation before add user
* refactor(test): free ports are now in settings
* fix: wait to create daemon user

feat(ports): set minimum port to expose

also do not assign public port for bases

issue #1531

refactor: display TLS

* refactor(backend): fix duplicated process req
* feat: clean db leftovers
* detect properly duplicated port
* refactor: store id_vm + port
* refactor(test): check port conflict
* refactor(test): copy config for mock domains
* check enforce limits properly
* check better port conflicts
* fix(install): correct id_vm
* properly test TLS
* : store port and vm to check duplicates
* show displays TLS
* clean cache when desconnecting VMs
* test: allow link sizes attribute
* test(displays): check gone TLS display when migrating
* install: clean ports before create index
* test ports with rvd_back running
* make sure there is an n_order field
*test ports and unload nbd when testing spinoff
* install: clean duplicated indexes
* refactor(test): tet mojo in background
* refactor(frontend): hide display URL unless port
* vlc no TLS
* refactor(test): clean iptables after test
* refactor(ports): improved fix conflict
* refactor(ports): manage secondary displays
* refactor: remove display_file pre-generated
* cache connections only if writeable
* user may have been removed
* retry 10 times to solve conflict

issue #1534

Two storage pools with the same name may point to
different mount points.

SQL comments crashed on dockerized mysql

issue #1510

fix(backend): remove conflicting prerouting

* test(ports); check duplicated internal ip
* feat(frontend): debug_ports setting

issue #1505

feat: bookings

* feat(cli): manage LDAP groups and users
* feat(frontend): manage LDAP groups and users

issue #1337

issue #1505

feat: displays