Add toolbar to Lexical rich text editor

[mddilley]

Now that the spike has proven that creating notes, editing notes, and capturing email contents is possible in Lexical, the next step is to add a toolbar with tools that are similar to the ones that we currently have available in react-quill. @tillyw shared the starter toolbar component that can be used as a starting place.

Current toolbar

Features to implement:

• Bold
• Italics
• Underline
• Strikethrough
• Ordered list
• Unordered list
• Hyperlinks
• Clear formatting of selected text (last priority and stretch goal)

[mddilley]

@tillyw could you estimate? Also we could look into how to get this from TSX -> JSX