Comma in check constraint value causes error with cli command schema:drop with Postgres

[jvdberg08]

Describe the bug
A clear and concise description of what the bug is.

When you have a check constraint with a value with a comma in it, trying to drop the schema through the CLI.
This happens due to the m2[1].split(',') here: https://github.com/mikro-orm/mikro-orm/blob/master/packages/postgresql/src/PostgreSqlSchemaHelper.ts#L150

Stack trace

TypeError: Cannot read properties of null (reading '1')
    at /home/jvdberg08/work/scopio/node_modules/@mikro-orm/postgresql/PostgreSqlSchemaHelper.js:125:59
    at Array.map (<anonymous>)
    at /home/jvdberg08/work/scopio/node_modules/@mikro-orm/postgresql/PostgreSqlSchemaHelper.js:123:55
    at Array.reduce (<anonymous>)
    at PostgreSqlSchemaHelper.getEnumDefinitions (/home/jvdberg08/work/scopio/node_modules/@mikro-orm/postgresql/PostgreSqlSchemaHelper.js:113:30)
    at Function.create (/home/jvdberg08/work/scopio/node_modules/@mikro-orm/knex/schema/DatabaseSchema.js:57:60)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async SchemaGenerator.getDropSchemaSQL (/home/jvdberg08/work/scopio/node_modules/@mikro-orm/knex/schema/SchemaGenerator.js:99:24)
    at async SchemaGenerator.dropSchema (/home/jvdberg08/work/scopio/node_modules/@mikro-orm/knex/schema/SchemaGenerator.js:73:21)
    at async Function.handleSchemaCommand (/home/jvdberg08/work/scopio/node_modules/@mikro-orm/cli/commands/SchemaCommandFactory.js:86:13)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

To Reproduce
Steps to reproduce the behavior:

1. Add an enum to an entity defined as export enum X { AB = 'A,B' }
2. Run migrations
3. yarn mikro-orm schema:drop -r throws an error.

Expected behavior
No error 😛

Additional context
Add any other context about the problem here.

Versions

Dependency	Version
node	16.13.0
typescript	4.7.2
mikro-orm	5.2.3
postgresql	5.2.3