* Convert shell plugin to internal plugin (#975)

The purpose of this PR is to embed the shell plugin in the main dkron binary, that will facilitate creating a single binary with the most important executor, for easy deployment using a single binary.

* Remove old UI (#984)
* Release a light image tag (#988)

Omit all plugins except the shell plugin that will be included in the main binary.

* Upgrade react admin to v4 (#1436)

* Use exponential backoff for retries (#1433)

* Handle ip changes (#1446)
* consul like approach: add server_lookup to make dkron independent from server node IP on raft layer
* handle memberupdate event
* query other servers before start & add test
* don't remove itself if node is a raft leader
* don't remove dkron server node if id matches

* Move config init to agent command (#1465)

Config init was being done on the root level command but only the agent command was using config values.

Now config init is done as pre-run of agent command only, getting rid of extra messages in other commands when the config was missing.

* Fix disabled (#1467)
* Embed http plugin (#1471)

http plugin is one of the most used plugins together with the shell plugin, embedding it in the main binary allow for more lean deployment.

* Show all Job fields
* Refactor buttons for admin v4

* Docs v4 (#1473)

* Reuse http clients with the same configuration (#1474)
* Update OpenAPI spec to v3.1.0 and add ACLs spec
* Refactor location of types as they not only belong to plugins, but used in general. (#1485)

Also add Pro protobuf and gen code as this should be public.

* Generate client
* Extend protobuf defs for ACLs
* Token fields
* Minor improvement in RabbitMQ executor (#1500)
* nice and forkable goreleaser (#1584)
* add support for hash scheduling (#1260)
* feat: Login form and admin update (#1589)

Upgrade react-admin to v5
Implements a login form to use in Pro version

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Co-authored-by: Victor Castell <victor@victorcastell.com>
Co-authored-by: Ivan Kripakov <108407979+ivan-kripakov-m10@users.noreply.github.com>
Co-authored-by: Filipe Pina <636320+fopina@users.noreply.github.com>