Have Update Project Link in navbar instead of as a button on Project Page

[rosiejeays]

• The current deployed product has the update project link in a button on the project page that only appears if the requested user is the project owner.
• Instead, it would look nicer to move it to the navbar, with the same conditional logic as is currently in place for the button (only appearing on the project page and only appearing if authenticated user is project owner)
• Code at the start of this branch partially does this, however the removal of the link is unreliable when moving away from project page, unless you reload the page or navigate to the project update page.