Bug 1785277 regressed performance in certain key areas of the debugger. Investigate and try to improve.

Set release status flags based on info from the regressing bug 1785277

This bug has the keyword regression, so its type should be defect.

Set release status flags based on info from the regressing bug 1785277

Lets also look into how we load source text especially around various kinds of location selection. Ideally we don't want to load it unnecessarily a couple of times, as load source text is not trivial, and can be a performance issue.
Example We might not need to loadSourceText here https://searchfox.org/mozilla-central/rev/83b86005c6913c2062419efb8aabdf2e683aa47f/devtools/client/debugger/src/actions/sources/prettyPrint.js#125-129 as we already do it here https://searchfox.org/mozilla-central/rev/b6d0ad6ba24b3d075e357e52160cd8fc7f911ba9/devtools/client/debugger/src/actions/sources/select.js#183

SideNote: We could probably also factorize setSymbols call as well.
And also while looking at this, it might be nice to await for dispatch(selectPrettyLocation(...)).

Note: Maybe we could move the location object to store full objects for the source and sourceActors rather than just the id's

Issues here are already fixed by the work in Bug 1818495