script plugin should support virtual directories

Background

script element cannot run remotely because it is not declared as BST_VIRTUAL_DIRECTORY.

Task description

• Support virtual directories in ScriptElement
• Declare BST_VIRTUAL_DIRECTORY in script.

Acceptance Criteria

Script elements should be able to execute remotely

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It seems that ScriptElement already does not use Sandbox.get_directory. That means script can already be tagged as BST_VIRTUAL_DIRECTORY.

I have tested it building Freedesktop SDK with BuildGrid.

mentioned in commit eb0dbcfc

mentioned in merge request !1047 (merged)

closed via merge request !1047 (merged)

mentioned in commit f7681925