Make dashboard columns configurable (PMT #95949)

Introduces bootstrap-table
fix for dashboard table classes
Use mdx_linkify on all the fields where we're using markdown

Fixes PMT #96043

I realized that we're not always saving markdown-generated HTML to the
database. This adds the 'linkify' extension wherever we use the markdown
template tag. Action item descriptions, user bios, etc should all have
correct link tags now.
Improvements to Add Tracker modal UI (PMT #96026)

Adds the AJAX response to the modal dialog, telling the user that their
form submission succeeded, or failed, and why.
Merge pull request #116 from nikolas/linkify-fields

Use mdx_linkify on all the fields where we're using markdown
Merge pull request #115 from nikolas/add-tracker-ui-improvement

Improvements to Add Tracker modal UI (PMT #96026)
merge conflict