Better user experience regarding restarting/auto-running qmlls

Steps to investigate
Hover your mouse cursor over the various warnings after each step below.

1. Use Qt Creator 13.0.0beta1 to load the attached project using Qt 6.7.0beta3. Load it from a new clean folder (no existing build folder, *.user file, or .qmlls.ini file)
2. Open MyApp/Main.qml
3. Build and run the project
4. Restart qmlls using the Language Server tool button)
5. After all the warnings (finally) disappear, click on the Language Server tool button again

Outcomes

• After Step #2, we have lots of warnings about being unable to import modules or resolve types (Expected, since the qmldir files have not yet been generated)
• After Step #3, we still see all the warnings (Not expected, since the required files have already been generated)
• After Step #4, the tooltips from hovering over the import statements and QML types no longer have warnings (Expected). However, the yellow Line Annotation warnings still persist for a long time (Not expected - all warnings should disappear at the same time)
• After Step #5, even after all the warnings have disappeared from screen, "Qmlls" does not appear under the Language Server tool button. Clicking "Inspect Language Clients" shows that qmlls has shut down but not restarted. (Not expected, since we asked it to restart)

Suggestions
From most important to least important:

• The Line Annotation warnings should be cleared very quickly after restarting qmlls
• qmlls should be asked to automtatically re-scan the build folder after the initial build is completed
• qmlls should start up again after being asked to restart