[Inbox] Option to resize text box when composing a message

[DeteesWuber]

Problem statement:

Currently, you cannot resize the text box when composing a message. This is especially inconvenient on small screens and with large amounts of content. The author loses the overview of the content.

Proposed solution:

Provide the flexibility to resize the text box when composing a message in Canvas Inbox.

User role(s):

admin,instructor,student,ta