Replace remaining deprecated view_component slot setters

What does this MR do and why?

This updates all remaining deprecated ViewComponent slot setter usages in our codebase.

The old way (c.SLOT_NAME) got deprecated in the later 2.x versions of the view_component gem and now got completely removed in the recent 3.0 release. We have to replace all deprecated calls before we can Upgrade to view_component v3.0 (#408988 - closed).

Because we had hundreds of lines in ~200 files to update, I do it in batches to get smaller, more reviewable MRs. This is one of them. See the checklist in #408988 (closed) for some already merged MRs.

Screenshots or screen recordings

No visual changes.

How to set up and validate locally

• We are currently on the latest 2.x version of the view_component gem. Both ways to set the slot work here, so there shouldn't be any functional changes, but feel free to browse around in the affected areas of the UI for a few samples.
• Focus on the diff itself. I've used a regular expression (find: (-|=) c\.(?!with_)(\w+) & replace: - c.with_$2) so please double-check that nothing unintentional was commited. Thanks!

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.