Replace the direct usage of ProgressIndicator with IProgressMonitor/ProgressMonitorAdapter

[tobous]

Saros/I still uses the ProgressIndicator interface provided by the IntelliJ API directly.

To offer a unified handling across the plugin, the wrapper ProgressMonitorAdater (or its interface IProgressMonitor) could be used instead. The current usages of ProgressIndicator should be looked at and it should be determined whether it is worth it to replace them.

This issues was previously discussed in #674 and #681.