* Update widgets gallery examples
* Update notepad example
* Update issues example
This change updates:
* Gradle to 7.1.1;
* AGP to 7.0.0;
* Compose to 1.0.0-alpha1-rc1;
* Kotlin to 1.5.21.
* Update image viewer example
This change removes `org.jetbrains.compose.desktop.application` plugin id
in favor of doing everything in `org.jetbrains.compose`.
The change simplifies configuring Compose Desktop projects.
Now, just one plugin dependency is needed.
To avoid task name conflicts with common task names such as `package` and `run`,
the plugin creates tasks lazily only if `application` block/property is used in a script.