Upgrade to Bootstrap 5

[madbob]

Upgrade for the Bootstrap preset to version 5.

• removed jQuery as a JS dependency, as it is no longer required
• removed .form-group classes (dropped)
• fixed mr- and ml- classes (replaced by me- and ms-)
• namespaced data attributes for JS plugins with the bs- prefix (here)

[dalpat]

I think this can be merged.

[taylorotwell]

Merged this - not sure why it's not showing merged.