More frontend fixes

[evildmp]

Pretty sure this contains everything that #55 does.

What it does:

• Adds a login button for users who aren't logged in
• Adds a URL field for projects so we can link to the documentation
• Adds an HTML5 date-picker in the frontend for last_review date
• Fixes the algorithm for calculating what level has been achieved for an objective
• Refreshes the initial_data.yaml
• Fixes a template bug: from {% if not perms.projects.change_condition %} to {% if not perms.projects.change_projectobjectivecondition %}
• Corrects some attributes in the template
• Adds a delay for some htmx operations to allow time for the server to respond
• Removes an unnecessary formset in the project template
• Reinstates Playwright tests

[dwilding]

Suggestions for this PR:

• Let's add a CI workflow that runs the application's tests. I've pushed some commits to do that. The tests are currently failing, but they should pass after we apply my other suggestions.

• Fix the application's tests. I ran into a couple of issues, one related to creating the superuser more than once, and one related to asserting changes too quickly. See comments.

• The new URL field is displaying correctly but the href is broken.

• Keep the test user in initial_data.yaml. I think you may have removed this by accident?

Suggestions for follow-up PRs:

• When looking at a project page, it would be nice to have a way to go back to the dashboard. Perhaps a "← back to dashboard" link/button next to the log in button?

• Once I've logged in, it's hard to tell that I'm logged in. Maybe some kind of global indicator and/or link to the admin area would be helpful?

[dwilding]

Tests passing. Merging so that the publishing workflow can start running.