by slashrsm: Simplify display classes.
by slashrsm: Simplify selection display classes naming.
by slashrsm: Simplify widget classes naming.
by slashrsm: Fix tests.
by slashrsm: Fix tests.
Merge pull request #20 from slashrsm/simplify_names

Simplify names
by slashrsm: Laverage event system to handle entity selection.
Issue #2350029 by kmoll: Create an "Upload" EntityBrowserWidget plugin type.
Merge pull request #21 from slashrsm/selected_event

by slashrsm: Leverage event system to handle entity selection.
Issue #2350029 by slashrsm: Minor fixes.
Merge pull request #22 from slashrsm/2350029

create an "Upload" EntityBrowserWidget plugin type