Script Server: Lint script in queue script dialog

As a user of the script server, I would like to lint my scripts before they are run and have warnings/errors displayed to me.

Acceptance criteria:

- [ ] GIVEN I run g.load_script(script) and get lint warnings/errors WHEN I enter the Queue script dialog AND load script into the dialog THEN the lint warnings/errors are displayed in the dialog
- [ ] GIVEN I have loaded a script with warnings/errors into the queue script dialog WHEN I click to queue the script THEN a warning dialog displays telling me I have errors AND I can choose to cancel queueing the script AND I can choose to continue queueing the script AND the choice is respected
- [ ] Lines that have errors/warnings are highlighted by colour and/or icon
- [ ] g.load_script and script server linters display same warnings/errors

The issue names g.load_script and the Queue script dialog as entry points; start by tracing how lint results reach the dialog and comparing both lint paths. Done means warnings and errors are shown with line indicators, queueing offers a respected cancel or continue choice, and both paths report the same diagnostics.

Scritto dal modello di indicizzazione a partire dal testo della issue.