Add configurable to manage per-gem data to intellij plugin

[valich]

The data collected might require removal due to different reasons (corrupted code, obsolete gem versions, etc) or even simple visual inspection.

One needs to create a configurable with an ability to:

1. See the installed/collected gem data
2. Clear data for particular/all gems
3. Manage the setting for collecting the local data

4. Manage the setting for sharing the data per gem

   This point arises from the scenario of internal gem usage.

[valich]

The current version