Fixes #10177

Regression from #6876

The condition introduced by #9998 was wrong, serializing boosts
that weren't self-boosts, and not serializing self-boosts.

The `hasMore` property of timelines in redux store was set whenever an API
request returned only one page of results, *even* if the query only requested
newer conversations (using `since_id`), causing `hasMore` to be incorrectly set to
false whenever fetching new toots in the direct timeline, which happens each time
the direct message column is opened.

(Basically #9516 for direct messages)

At 480px height, there is not enough space to fully display the footer.

`::FetchRemoteAccountService` is not `ActivityPub::FetchRemoteAccountService`,
its second argument is the pre-fetched body. Passing `id: false` actually passed
a `Hash` as the prefetched body, instead of properly resolving unknown remote
accounts.

Regression from #7311

Same as #8220 but for reports

* Never return empty participants for conversations

Fixes #10068

* Fix client-side crash when conversations have no participants

Since the “domain” field is ignored in this case.

Regression from #9581

Fix #8785

Fix #9350

Fix #6060

Fix #9922

Fix #9190

fix #10045

* Add image descriptions to searchable post content.

* Allow multi-line image descriptions.

* Request image descriptions in the same query as posts when creating the search index.

(see https://github.com/tootsuite/mastodon/pull/10036#discussion_r256551624)

* Revert "Change robots.txt to exclude some URLs (#10037)"

This reverts commit 80161f43.

* Let's block media_proxy

/media_proxy/ is a dynamic route used for requesting uncached media, so it's
probably bad to let crawlers use it

* misleading comment

- Exclude static assets
- Exclude uploaded files
- Exclude alternate versions of the profile page
- Exclude media proxy URLs

Fix #10033

Regression from #9998

* Filter incoming Announce activities by relation to local activity

Reject if announcer is not followed by local accounts, and is not
from an enabled relay, and the object is not a local status

Follow-up to #10005

* Fix tests

Reject those from accounts with no local followers, from relays
that are not enabled, which do not address local accounts and are
not replies to accounts that do have local followers

* When self-boosting, embed original toot into Announce serialization

* Process unknown self-boosts from Announce object if it is more than an URI

* Add some self-boost specs

* Only serialize private toots in self-Announces

* Create Redisable

* Use #redis instead of Redis.current