Styles module: Add option to suppress preview

[deekayhd]

Is your feature request related to a problem? Please describe.
This feature request originated from the post In the lighttable view, is there a way to turn off the styles preview when hovering? on pixls.us.
The tooltip of a style in the styles module in lighttable contains a preview of the style applied to the selected image. Especially, on computers without a GPU it may take some time until the preview is rendered and shown. During this time the UI is non-reacting. This is especially annoying when accidentally hovering over a style while moving the mouse.

Describe the solution you'd like
I propose to introduce an option to suppress the creation and display of the preview as shown in the screenshot below.
The default of the setting would be "active", so that the current behavior is not changed.

Alternatives
New global preference: A pro of this option is that no UI change of the module is necessary. However, a user may want to activate the preview for an image or styla individually. Switching in the global preferences would then be inconvenient.
Module settings: Again no UI change of the main module screen necessary, but switching is still more complex than with the option on the main screen. Besides, it seems overkill to introduce the settings dialog for only one checkbox.

Additional context
Proposed UI change:

I already have the change ready in my fork and can provide a PR, if the proposal may be considered.