sosreport: Rewrite in React

[martinpitt]

Drop sosreport.scss, there is no remaining custom CSS.

Move from the deprecated sosreport command to sos report. All our
supported OSes have that now.

Close the dialog when downloading the report succeeds.

Rename the dialog from #sos to #sos-dialog to be consistent with
other dialogs.

This fixes the untranslatable modal dialog title, which previously got
mis-parsed from the HTML (https://bugzilla.redhat.com/show_bug.cgi?id=2018417).

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• Fix broken message IDs/translations in weblate; can we fix the .po files in source?

Page:

main:

This PR, virtually indistinguishable:

dialog in progress:

main:

This PR, fixed icon, close button, progress percentage, cancel is secondary:

dialog done:

This PR , download button now in footer, redundant close button removed in favor of "x" button:

dialog error:

main:

This PR, danger downgraded to warning, secondary button instead of link, better formatting of error details:

[martinpitt]

Nice, all tests were green on the first try! I cleaned up the error page a bit still.

@garrett , this is a "keep original design to 90% with just some obvious standardizations" rewrite, to pave the way for #15875. I'd appreciate a quick look on the design changes, to make sure I didn't make anything worse. I put before/after screenshots into the description.

[martinpitt]

Updated for converting single buttons from link to secondary, dropped the redundant "Close" button from the "finished" dialog state. Thanks @garrett for reviewing! Screenshots in description updated.

[garrett]

This works for me for a 1:1 port (with a few little improvements as a bonus).

We should redesign this at some point so it doesn't rely on everything being in modals (especially if the report persists or if multiple reports persist), but that's outside the scope of this PR.