When Converse runs inside a browser extension, enable browser sync and local storage for persistent storage

In MUCs, messages are fetched too late in order for it to be practical
to wait for messages before rendering various parts of the MUC view.

Previously there was a bug, in the sense that `messages.fetched` was
`undefined` when being `await`ed in `updateAfterMessagesFetched`.
Once this was fixed, this issue became clear.

since we create the `fetched` promise earlier

Fixes #2241

When we're showing only one chat at a time, we want to make sure that
all other chats have their `hidden` flag set to `true`.

Previously this was done in chatboxviews, but given that we want to
render UI based on state, this should be done in the headless part of
Converse.

As a result of the changes, the `beforeShowingChatView` has been
removed.

https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent/CustomEvent

In the process, turn it into a component

* keep message in place after edition by assigning previous message original timestamp
* update time displayed to keep current behaviour
* add test to check a message remains in the same position of the history after being edited
* briefly describe pr changes in changelog

- `allow_user_trust_override`
- `clear_cache_on_logout`

The `persistent_store` setting can now also be set to `sessionStorage`

The `trusted` settings was in effect playing the role of two separate settings
and implicitly affecting a third ('persistent_store').

By breaking it up, we make things more explicit and allow for new
configurations. For example, clearing the cache on logout, while using
some kind of persistent store.

Bumps [elliptic](https://github.com/indutny/elliptic) from 6.5.2 to 6.5.3. **This update includes a security fix.**
- [Release notes](https://github.com/indutny/elliptic/releases)
- [Commits](https://github.com/indutny/elliptic/compare/v6.5.2...v6.5.3)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

use muc-toolbar-btn-color for background

* allow the use of MUC affiliation, MUC role, and VCard roles as hats
* update setting documentation
* remove filter from VCard roles
* update naming and documentation to make explicit the use of XEP-317 Hats
* include muc_hats config option update to changelog

* notify changes to client on bookmark-update
* update XEP-115 caps verification string

in 1:1 chats.

See: https://xmpp.org/extensions/xep-0313.html#archives_id

* regression of #1317: Don't show errors for CSI messages
* fix failing tests

- Let `api.rooms.open` call `api.rooms.get` directly, instead of indirectly via `api.rooms.create`
- Remove the `createChatRoom` function
- Also strip URI parts from JID in `api.rooms.get` and use utility method for doing so

Bumps [http-proxy](https://github.com/http-party/node-http-proxy) from 1.18.0 to 1.18.1.
- [Release notes](https://github.com/http-party/node-http-proxy/releases)
- [Changelog](https://github.com/http-party/node-http-proxy/blob/master/CHANGELOG.md)
- [Commits](https://github.com/http-party/node-http-proxy/compare/1.18.0...1.18.1)
Signed-off-by: dependabot[bot] <support@github.com>

* #1829 css var instead of hard coded colors

Bumps [dot-prop](https://github.com/sindresorhus/dot-prop) from 4.2.0 to 4.2.1. **This update includes a security fix.**
- [Release notes](https://github.com/sindresorhus/dot-prop/releases)
- [Commits](https://github.com/sindresorhus/dot-prop/commits)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>