Use a common share function

[jesscmoore]

Description

Currently I use different functions for sharing an user own note and an externally owned note. Similarly for viewing and editing notes. In preparation to moving towards a common data model, migrate to a single share note function and likewise for viewing and editing functions.

Why

So that as a developer, the function call is the same regardless of if it is an own note or external note. Reducing duplicate code and technical debt for the migration to being able to show own notes and externally owned notes in a single view.

Closing Criteria

Checklist for closing the issue:

• No errors from make prep
• All tests pass make qtest
• share on both own notes and externally owned notes.

[jesscmoore]

In this issue, I've just unified the share_note class to work for owner's notes and external notes. Unifying the view and edit classes requires a common data model implemented first.