Fix add group

[panivita]

Description

work on fixing adding a new room, need to add all users to channels_members, now only one user. Also, work on adding the current user as channel members to the newly created room. Add code from this task 'Image component added to RoomForm #301', I talk with Aswini about that. Because I change many files, she worked with the previous version. Add imageUrl to createchannel in channel-controller. When the user uploads the image, we create a new channel with the title, image URL, and send all data to the server.

Fixes # (issue)

How to test?

Click to create a new room button, add people, upload images and write the name of the group, write a message, you will see your message, and the new group in the list of the last conversation on the overview page.

Checklist

• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have made corresponding changes to the documentation
• [x] This PR is ready to be merged and not breaking any other functionality

[panivita]

[panivita]