* Fix compatibility with Intellij 2021.3
Resolves#1373
* Use Java reflection
* Set Java source & target compatibility for build helpers
Otherwise, Gradle might set Gradle metadata attributes in such way,
that transitive dependencies of published modules are not resolved
* Configure shadow jar manually
Applying plugin configures additional publication,
so that both .jar and -shadow.jar are published,
and additional configurations are added to Gradle metadata.
To avoid unexpected metadata resolution results,
ShadowJar task is now configured manually
* Fix closeStagingRepo JSON request
* Update publishing build-helpers in compose
* Activate preview toolwindow on receiving preview configuration
* Don't show preview toolwindow until a preview is requested
* Add icon to preview toolwindow
Alexey Tsvetkov
Alexey Tsvetkov