Revert subscription refactoring.

See merge request pleroma/pleroma!1741

As discussed in pleroma-meta#2

This reverts commit eb9aa7aa1095de150d036839c78c402019efb4b1, reversing
changes made to c4fbb56984.

Mastodon API: add follow_requests_count

See merge request pleroma/pleroma!1726

!1691 is a breaking change + documentation fixes

See merge request pleroma/pleroma!1739

[ci skip]

Similar to how the other responses examples are done,
this also makes it proper JSON (as it doesn’t have comments).

!1691: https://git.pleroma.social/pleroma/pleroma/merge_requests/1691

Update admin_api.md

See merge request pleroma/pleroma!1738

tests for mastodon_api_controller.ex

See merge request pleroma/pleroma!1639

status_controller.ex: Posting media status without content defined

See merge request pleroma/pleroma!1735

Fix not being able to post empty statuses with attachments

See merge request pleroma/pleroma!1734

Attachment field was filled in after the empty status check

Add `remote_ip` plug

See merge request pleroma/pleroma!1608

Extract follow requests actions from `MastodonAPIController` to `FollowRequestController`

See merge request pleroma/pleroma!1730

Extract domain blocks actions from `MastodonAPIController` to `DomainBlockController`

See merge request pleroma/pleroma!1729

Extract scheduled statuses actions from `MastodonAPIController` to `ScheduledActivityController`

See merge request pleroma/pleroma!1728

Extract filter actions from `MastodonAPIController` to `FilterController`

See merge request pleroma/pleroma!1725

Fix SubscriptionNotificationView

See merge request pleroma/pleroma!1727

Extract status actions from `MastodonAPIController` to `StatusController`

See merge request pleroma/pleroma!1719

Refactor subscription functionality

Closes #1130

See merge request pleroma/pleroma!1664

Minor corrections and clarification for Alpine standard v.3.10

See merge request pleroma/pleroma!1594

Update Japanese document to follow English document

See merge request pleroma/pleroma!1615

Add list_from endpoint to the pleroma_api docs

See merge request pleroma/pleroma!1720

Fix code block for admin api document

See merge request pleroma/pleroma!1722

Refactor `CommonAPI.post/2`

See merge request pleroma/pleroma!1713

Extract timeline actions from `MastodonAPIController` into `TimelineController`

See merge request pleroma/pleroma!1648

Sync changelogs between master and develop

See merge request pleroma/pleroma!1724

Moderation log filters

See merge request pleroma/pleroma!1607