Join request dialog

[em66850]

Dialog box for join requests. It is fixed in the bottom right.

Still need to add tests.

Currently the dialog does not resize if the username is too long (if it takes up more than 2 lines it will be cut off). We could enforce a username character limit or have the dialog resize when the text does not fit.

Right now the dialog appears when you press the "test" button on the start screen (this is for debugging purposes and will be removed when the trigger for the dialog is implemented)

[em66850]

Updated the dialog box so the username can overflow if it does not fit, but the message will no longer overflow off the box.

[em66850]

Due to the issues with the UI testing framework, we can't test the dialog box in this PR. We'll have to test it with the message sender/receiver classes once the dialog box is used (to make sure it returns the correct results). I tested it manually with print statements and can confirm that it does return the expected values but we will need automated tests when possible.

The code to call the dialog box and get to result is commented out in the start screen controller so it can be moved to the right place in the code.

Resolves #46