Show obs - convert turbo-frame tags to div

[nimmolo]

Lower-maintenance solution for turbo updates on the show obs page:

We don't have to use <turbo-frame> tags for "surgical" updates to the DOM. <div> with an id is enough.

Switching to <div>s also means we don't need any special data attributes on nested <a> links. That's because links within a turbo-frame expect a response that replaces the turbo-frame they are nested within, and not a new page. (#2036) It seems like a gotcha that will confuse future developers.

Note: there's a separate existing issue here, and I don't know how or if it's related: #2039
Update: it wasn't related, but this PR fixes the issue. The obs id wasn't getting passed to the re-rendered new HR/CN links, so the links didn't work.

[coveralls]

coverage: 94.428% (+0.003%) from 94.425%
when pulling 2f0120a on nimmo-convert-turbo-frames-to-divs-show-obs
into 155f008 on main.

[nimmolo]

@mo-nathan Should I maybe merge this, and sort out the existing delete/add refresh issue in a separate PR?

[mo-nathan]

Looks good to me. I was not able to reproduce the behavior reported in #2039.