Clean up Scheduled Jobs admin page

[larssandergreen]

Before

Table overflowing because of use of <pre> tags.
Execute Now hidden under menu, when I think this is much more commonly used than Edit.
One PHP8 warning.

After

Table no longer overflows, params shown with nl2br.
Execute easily accessible, name shortened (this translation string already exists).
No warning.

Maybe not ideal display of params, but better than having the table overflow a lot. If you need to seriously examine the params, you can still click through to edit. Only a few scheduled jobs have params by default.

[civibot]

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[colemanw]

FYI @aydun is working to replace this entire screen. See #26060

[larssandergreen]

@colemanw Ah, oh well, should have checked. I think still worth fixing the broken table here though.

[colemanw]

No it's fine @larssandergreen - the Admin UI Extension is still optional so it's not going to get replaced right away. It was just an FYI.
This PR is still good. Thanks.