Rework the file menu so that it no longer relies on having a reference to the media delegate to manage a download for either opening externally or copying to clipboard. This allows the menus to be moved out of the delegates and maximize components and have them accessed through RoomManager. This reduces duplication and reduces the number of components in an already heavy delegate.
Similar to text handler, pull out the disparate array of functions which format information from an event ready for display in the UI and put in a handler class with a test suite.
requires https://github.com/quotient-im/libQuotient/pull/686
Add a tab bar to the room drawer which includes a new media tab in addition to the room information tab. This mr completes the architecture for adding others easily later e.g. message highlights or threads.
To put this together I had to make sure things like the menus and the maximize delegate were available to both the room drawer and page so there is some rework there to put it all together.
Wide\

Mobile\

Create a media model for all the media message in the timeline and then setup `NeoChatMaximizeComponent` so that it can use the media model to scroll through all loaded images and video in the current room.
Depends upon libraries/kirigami-addons!105
FEATURE: 467411
Create a cpp helper class to calculate the correct delegate width given it's parent width.
This is designed to be more robust and hopefully easier to understand than the current mass of javascript calcs.
BUG: 470167
Always use `NeoChatRoom::getUser` for getting user details in a room context.
- `MessageEventModel` now calls `getUser`
- `getUser` is now overloaded to also be able to take a `NeoChatUser*`
- add params to `getUser` that are needed for the model outputs
Create a reaction model that provides all the required data for `ReactionDelegate` so that none need to be calculated in QML.
This also cleans up the API for `ReactionDelegate`
Limit the maximum number of avatars shown for other user read markers and collapsed state events
For state events \

For read markers \

Create a `messageeventmodel` role for media info and reply media info that is a QMap with all the required data.
This replaces the MediaUrlRole, FileMimeTypeRole and the ContentTypeRole. The reply role no longer needs the content role.
This also ensures mxc urls are now generated for replies. All the media parameters will now have default values assigned in the model so the QML no longer needs to do this.
- Update the message event and user models so that the full source url is output.
- Separate the reply author into its own role
- Create an empty user object that can be passed so that the QML code no longer needs to check if certain parameters exist.
- Make avatarForMember return and empty QUrl if a valid avatar cannot be found and make use in the user and event models
As well as cleaning up the QML this should also stop the QML Image: Media id '' doesn't follow server/mediaId pattern spam in the log.
Update the base item in the timeline container to be a column layout. This means that all the items can be laid out automatically without the need to set lots of manual settings and anchoring.
The overall height calculation for the delegate is vastly simplified (in fact it is removed) which deals with the fact that there were still instances where the manual calculation didn't work e.g. a delegate with a reaction followed by another message from the same user didn't give the correct bottom margin (see below)
before:

after:

This also improves upon the recently changed hover highlight behaviour. The previous patched moved it to cover the avatar as well as the bubble however it also covered the section and reaction when present which didn't look good. The highlight now only covers the avatar and bubble
before:

after:

This also cleans up some of the margins in both bubble and compact to ensure consistency.
**Updated**
Add a section label at the top which shows the date label of the next section up. This means that the user will always be able to see the date of all messages on screen.

From the feedback given I've added a background at the top. I also added an underline to the heading which applies both at the top and in the listView since they use the same component. I added it originally for the top because I felt it looked a bit weird having messages appear from behind a heading background the same colour as the listView background.
Note: I know the gaps between messages are not right. I had to set the spacing in the listView to 0 to prevent itemAt returning null. I plan to add it back in as part of the delegate code before it would be merge.
Fixes BUG:454880