Revert "Issue #3038365 by acbramley, Grimreaper, smustgrave, catch: Add owner to the BlockContent entity type"

This reverts commit b8d5c0e4.

Issue #3038365 by acbramley, Grimreaper, smustgrave, catch: Add owner to the BlockContent entity type

Issue #3258430 by mattjones86, smustgrave, larowlan, Berdir: Block Content database index for reusable column

Issue #2317981 by benjifisher, ohthehugemanatee, larowlan, andypost, ByronNorris, AaronMcHale, smustgrave, dawehner, rkoller: Move block content edit and delete routes under admin/content/block to improve IA for editors and fix breadcrumbs

Issue #3318549 by smustgrave, mstrelan, larowlan, rkoller, AaronMcHale, acbramley: Rename Custom Block terminology in the admin UI

Issue #3272969 by LOBsTerr, smustgrave, metasim, larowlan, Abhijith S, Devashish Jangid, johnwebdev, vakulrai, tedbow, ranjith_kumar_k_u, nghai: Remove unique constraint on block content info field

Issue #1984588 by dpi, larowlan, AaronMcHale, smustgrave, xjm, acbramley: Add Block Content revision UI

Revert "Issue #1984588 by dpi, larowlan, AaronMcHale, smustgrave, acbramley: Add Block Content revision UI"

This reverts commit 86caf6f3.

Issue #3087644 by jibran, Berdir, alexpott, longwave, Wim Leers, amateescu, catch, xjm, larowlan, dpi, quietone: Remove Drupal 8 updates up to and including 88**

Revert "Issue #3087644 by jibran, Berdir, alexpott, longwave, Wim Leers, amateescu, catch, larowlan, dpi, quietone: Remove Drupal 8 updates up to and including 88**"

This reverts commit 136f0550.

Issue #3087644 by jibran, Berdir, alexpott, longwave, Wim Leers, amateescu, catch, larowlan, dpi, quietone: Remove Drupal 8 updates up to and including 88**

Issue #2991902 by amateescu: Fix block_content_update_8400() and taxonomy_update_8601() to not rely on the module handler anymore

Issue #2976334 by tedbow, Wim Leers, johndevman, tim.plunkett, phenaproxima, larowlan, samuel.mortenson, Berdir, EclipseGc, johnzzon: Allow Custom blocks to be set as non-reusable adding access restriction based on where it was used

Issue #2951242 by alexpott, amateescu, bmunslow, Berdir, greg606, donaldp: Allow BaseFieldDefinition::setInitialValueFromField() to set a default value - this fixes issues with block_content_update_8400()

Issue #2820848 by timmillwood, amateescu, Pavan B S, Berdir, Jo Fitzgerald, claudiu.cristea: Make BlockContent entities publishable

Issue #2716081 by timmillwood, dixon_: BlockContent should have revision_user and revision_created fields and implement RevisionLogInterface

Issue #2415335 by phenaproxima, miguelc303, quietone, mikeryan: Migration Files for Drupal 7 Custom Blocks

Issue #2542748 by plach, effulgentsia, jhedstrom, Gábor Hojtsy, alexpott, mpdonadio, catch, dawehner: Automatic entity updates can fail when there is existing content, leaving the site's schema in an unpredictable state

Issue #1920862 by martin107, Mixologic, cilefen, larowlan, xan.ps, tim.plunkett | sun: Rename custom_block.module to block_content.module.