pleroma.instance: Fix Exiftool module name

See merge request pleroma/pleroma!3143

fixes 2034 Make notifs view work for reports

Closes #2034

See merge request pleroma/pleroma!2912

* These are the first small steps for issue 2034 "Reports should send a notification to admins".
* I added a new type of notification "pleroma:report" to the the database manually (a migration will need to be written later)
* I added the new type to the notification_controller
* I made the view return the notification. It doesn't include the report itself (yet)

First draft of tips for optimizing BEAM

See merge request pleroma/pleroma!3123

remove PurgeExpiredActivity from Oban db config

See merge request pleroma/pleroma!3137

Install file-dev in Dockerfile build stage

See merge request pleroma/pleroma!3135

This is required by the majic, added in #2534.

Validate the content-type of the response when fetching an object,
according to https://www.w3.org/TR/activitypub/#x3-2-retrieving-objects.

content-type headers had to be added to many mocks in order to support
this, some of this was done with a regex. While I did go over the
resulting files to check I didn't modify anything unrelated, there is a
 possibility I missed something.

Closes pleroma#1948

Title injection change

See merge request pleroma/pleroma!3132

Ingest blurhash for attachments if they were federated

Closes #2294

See merge request pleroma/pleroma!3133

little changes for MRF config descriptions

See merge request pleroma/pleroma!3131

- log level reduction, if policy doesn't implement config_description method
- docs in dev.md

Config descriptions for custom MRF policies

Closes #2222

See merge request pleroma/pleroma!3128

- revert UserAllowPolicy description
- MRF descriptions order

Resolve "Wrong user link in Report email"

Closes #2260

See merge request pleroma/pleroma!3121

Fix title on load of Pleroma HTML, fixes #2281

Closes #2281

See merge request pleroma/pleroma!3125

Escaping in xml templates

Closes #2291

See merge request pleroma/pleroma!3126

Remove release_env

See merge request pleroma/pleroma!3124

While taking a final look at instance.gen before releasing I noticed
that the release_env task outputs messages in broken english. Upon
further inspection it seems to have even more severe issues which, in
my opinion, warrant it's at least temporary removal:
- We do not explain what it actually does, anywhere. Neither the task
 docs nor instance.gen, nor installation instructions.
- It does not respect FHS on OTP releases (uses /opt/pleroma/config even
 though we store the config in /etc/pleroma/config.exs).
- It doesn't work on OTP releases, which is the main reason it exists.
Neither systemd nor openrc service files for OTP include it.
- It is not mentioned in install guides other than the ones for Debian
and OTP releases.

Expiring mutes for users and activities

Closes #1817

See merge request pleroma/pleroma!2971

don't run  Stats GenServer updates in tests

See merge request pleroma/pleroma!2976

Add TagPolicy as default MRF

See merge request pleroma/pleroma!2834