[VSCode extension] Allow setting 'netbeans.jdkhome' on a per-workspace basis.

### Description

Allow setting `netbeans.jdkhome` on a per-workspace basis in the VSCode extension.

### Use case/motivation

I use different jdks for different work spaces. However, currently it is only possible to set the used jdk globally, which means I have to change the setting every time I switch to working on a project which uses a different jdk.

When I try to set it in the settings of a workspace I get the message: "This setting can only be applied in user settings..." (see image)


### Related issues

_No response_

### Are you willing to submit a pull request?

No

Start by locating the VSCode extension's registration and handling of the `netbeans.jdkhome` setting. Verify how user and workspace settings are distinguished, then confirm that a workspace value can override the global value and selects the JDK used by the extension.

Written by the indexing model from the issue text.