entity_browser 8.x-1.0-alpha6

Entity browser 8.x-1.0-alpha6
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- #2764747 by marcoscano: Example module cannot be uninstalled and installed back
- #2639706 by slashrsm, samuel.mortenson: Use entity type manager pt. 2.
- #2656196 by webflo, slashrsm, chr.fritsch, phenaproxima: Allow initialization of the entity browser with the existing selection.
- #2639706 by heykarthikwithu, slashrsm, borisson_, marvin_B8, killua99: Replace the entity manager with the entity type manager and remove unused imports in code base
- by slashrsm: Fix fatal.
- CodeSniffer auto correct.
- #2750995 by marcoscano, slashrsm, daniel.bosen, samuel.mortenson: Browser creation wizard should not trigger validation on delete action.
- #2758767 by phenaproxima, slashrsm: Fix render caching problem with EB views bulk form element.
- #2760359 by slashrsm, paranojik: Drupal\entity_browser\Plugin\Field\FieldWidget\EntityReference::errorElement() shouldn't return NULL
- #2747853 by SylvainM, DeFr, slashrsm: Widget remove button triggers entity custom validation