2.0.4: Add drag & drop files & message-avatar slot & search-room event

Changelog

• Add the possibility to drag & drop files #336
• Export register function in TS definition #379
• Fix multiple edit / reply actions #380
• Add message-avatar_{{MESSAGE_ID}} slot #372
• Add custom-search-room-enabled prop and search-room event to use custom room search event 8976dc4