Make turbo progress bar optional

[omarluq]

Adding Morph to Turbo has genuinely been a game changer—big thanks for all the effort in enhancing Turbo! While the Turbo progress bar's default setup during a refresh is understandable, having the flexibility to disable it, either across the board or per stream, could be really handy, e.g.

globally:

<meta name="turbo-refresh-method" content="morph"  progress-bar="none">

Or for specific streams:

<turbo-stream action="refresh" progress-bar="none">
</turbo-stream>

[rbclark]

Definitely agree, duplicate of #1211