Add a space homepage with the ability to both create new room and add existing rooms to the space. This uses a tree model for the space hierarchy and will go to any number of levels. The user should only see the add options if they have appropriate permissions.
This MR also combines the create space and room pages and adds a lot of optional functionality for managing space children.

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\

Add handling for new default push rules added in 1.7 also add a generic unknown handling for if any others are added in the future so they don't appear in keywords
Merge the functionality of CollapseStateProxyModel into MessageFilterModel there is no need for a whole separate model the filters can be combined trivialy.
In some cases (where we don't get a thumbnail) we load the entire image,
which might be large. Even when we get a thumbnail, the smoothing we
apply doesn't get the best results and the only other option is
mipmapping which is more memory intensive - it stores progressively
smaller images but keeps all of them in memory.
Now the ImageDelegate sets the sourceSize, which helps reduce the memory
footprint (since Qt will throw away whatever parts of the image we don't
need) and makes the images look smoother when scaled. However,
AnimatedImages do not support this so this change introduces a new
property to tell if the image could possibly be animated. It will
erroneously pick up formats that could support animation (e.g. WebP) but
other image formats will still benefit so it's a net positive. The
ImageDelegate will load the correct image component depending on this
property.
When auto-completing rooms, there may be some that do not have
canonical addresses (e.g. 1-to-1 chats). These can't be linked anyway,
so skip them and any other unlinkable entries.