Mastodon API: Preloading and normalization optimizations

See merge request pleroma/pleroma!1558

Nicer formatting for safe_render errors

See merge request pleroma/pleroma!1560

tests for Web/ActivityPub/Relay

See merge request pleroma/pleroma!1557

tests for /web/mastodon_api/mastodon_api.ex

See merge request pleroma/pleroma!1554

- Try to normalize the activity instead of object wherever possible
- Put the `user` key on non-home timelines as well so bookmarks and
thread mutes are preloaded there as well
- Skip trying to get the user when rendering mentions if the id ==
as:Public or user's follower collection
- Preload the object when getting replied to activities and do not crash
if it's not present

This almost solves the problem of Pleroma hammering the db with a lot
of queries when rendering timelines, the things left are
1. When rendering mentions and the user is not in cache, save it for
later and request all uncached users in one go
2. Somehow get rid of needing to get the latest follow activity to
detect the value of `requested` in a relationship. (create a database
view for user relationship and cache it maybe?)

config: remove legacy activitypub accept_blocks setting

See merge request pleroma/pleroma!1556

Anyone who is interested in dropping blocks can write their own MRF
policy at this point.  This setting predated the MRF framework.

Disabling the side effect (unsubscription) is still a config option
per policy.

Update AdminFE

See merge request pleroma/pleroma!1555

Now permits server configuration. Consider this ALPHA.

According to gargron, this is the intended usage.

Add a changelog entry for !1552

See merge request pleroma/pleroma!1553

Do not fetch the reply object in `fix_type` unless the object has the `name` key and use a depth limit when fetching it

See merge request pleroma/pleroma!1552

`name` key and use a depth limit when fetching it

MRF: ensure that subdomain_match calls are case-insensitive

See merge request pleroma/pleroma!1550

Mastodon API: Set follower/following counters to 0 when hiding followers/following is enabled

See merge request pleroma/pleroma!1544

# Conflicts:
#   CHANGELOG.md

Strip internal fields including likes from incoming and outgoing activities

Closes #1159

See merge request pleroma/pleroma!1533

tests for Pleroma.Uploaders

See merge request pleroma/pleroma!1543

Mastodon API: Fix thread mute detection

See merge request pleroma/pleroma!1548

It was calling CommonAPI.thread_muted? with post author's account
instead of viewer's one.

Uploader.S3 added support stream uploads

See merge request pleroma/pleroma!1545

followers/following is enabled

We are already doing that in AP representation, so I think we should do
it here as well for consistency.

Feature/digest email

See merge request pleroma/pleroma!1078