Not all users might be migrated from CRW to Devspaces

We fetch all users [1] during migration from CRW to Devspaces.
Unfortunately keycloak returns the very first page of users. It is ~100 users.
All others will be ignored during migration.

There are 2 solutions:

• add `?max=65535` to the request in [1]
• rework script to fetch users by pages

[1] https://github.com/eclipse-che/che-docs/blob/b4fab46825905d2d1f17e6906bb67c3623eab001/modules/administration-guide/attachments/migration/1-prepare.sh#L64