Revert "Issue #1923406 by stefan.r, yannickoo: Use ASCII character set on alphanumeric fields so we can index all 255 characters"

This reverts commit ac4e35ce.

Issue #1923406 by stefan.r, yannickoo: Use ASCII character set on alphanumeric fields so we can index all 255 characters

Issue #2447555 by Cinnead: Unnecessary index on langcode and deleted column in dedicated field tables

Issue #2340993 by Berdir: SqlContentEntityStorageSchema::requiresEntityDataMigration() returns TRUE for cases where it should return FALSE

Issue #2419065 by jhedstrom: Switching the entity storage class should not be considered a definition update that requires schema changes

Issue #2363099 by Gábor Hojtsy, Berdir, swentel, plach: Using translated field definition descriptions in entity schema results in different schema definitions, resulting in update.php changes

Issue #2371605 by plach, larowlan: SqlContentEntityStorage::countFieldData() fatals for revision metadata fields and the UUID field

Issue #2232477 by plach, yched, tstoeckler, amateescu: Fatal when adding new fields with NOT NULL constraints in a base table that contains existing entities

Issue #2143729 by tstoeckler, plach, jsbalsera, Berdir, mauzeh, damiankloip, andypost: Entity definitions miss a language entity key

Issue #2335879 by alexpott, dixon_, Wim Leers, chx, mauzeh, ygerasimov, jeqq: Change SqlContentEntityStorageSchema::requiresEntityDataMigration() to ask the old storage handler if it has data rather than assuming yes unless NULL storage

Issue #2328919 by Mile23, YesCT, tim.plunkett: Remove () from a bunch of @covers definitions in PHPUnit

Revert "Issue #2232477 by tstoeckler, a 'fliptable' mateescu, plach: Fixed Fatal when adding new fields with NOT NULL constraints in a base table that contains existing entities."

This reverts commit 08d3ebba.

Issue #2232477 by tstoeckler, a 'fliptable' mateescu, plach: Fixed Fatal when adding new fields with NOT NULL constraints in a base table that contains existing entities.

Issue #2337927 by effulgentsia, plach, fago: Fixed SqlContentEntityStorage::onFieldStorageDefinition(Create|Update|Delete)() is broken for base fields.

Issue #2330121 by plach, effulgentsia, fago: Replace ContentEntityDatabaseStorage::getSchema() with a new EntityTypeListenerInterface implemented by SqlContentEntityStorageSchema.

Issue #2326949 by plach, effulgentsia: Move entity-type-specific schema information from the storage class to a schema handler.

Issue #697760 by sun: Replace getInfo() in tests with native phpDoc + annotations (following PHPUnit).

Issue #2143291 by plach, alexpott, xjm, effulgentsia, pwolanin, swentel | yched: Clarify handling of field translatability.

Issue #2183231 by tstoeckler, plach, jessebeach, fago, Berdir, xjm, mauzeh: Make ContentEntityDatabaseStorage generate static database schemas for content entities.