Add changelog for 10.0.0-beta.1

[nickvergessen]

Added

• Implement unified search for messages #4017
• Support for user status #3993
• Moderators can now mute all participants in the moderator menu #4052
• Allow changing the camera and microphone during a call #4023
• Show upload progress and a preview when sharing a file into the chat #3988
• Add a dashboard widget with unread mentions and active calls #3890
• Add an emoji picker to the chat #3994
• Hosted high-performance backend trial option in the admin settings #3620
• 🚧 TechPreview: Matterbridge integration #4010
• Compatibility with Nextcloud 20

Changed

• Allow to select your own video #3814

Fixed

• Scroll to the original message when clicking on a quota #4037
• Fix transparency issue with the avatar menu in the participant list #3958
• Prevent infinite loop in datachannel open re-transmission #3882

Pending PRs:

• spreed#3732 Send offer again when own peer is not initially connected @danxuliu
• spreed#3804 Handle error when joining room in the external signaling server @danxuliu
• spreed#3931 Add scroll to bottom button @ma12-co
• spreed#4064 Add padding to new group conversation's tooltip @ma12-co