Reject invalid tenant ids

@Julian Ladisch will take a look to see where this stands and the security team can discuss next steps afterwards

Work reverted . There's a PR which allows existing tenant ID - see https://folio-org.atlassian.net/browse/OKAPI-1121#icft=OKAPI-1121

The security team has reviewed this and assigned priority. Ideally we can get this fixed in Morning Glory.

Next steps:

1. @Julian Ladisch to discuss the set of restrictions with the core-platform team.

2. Reach out to the implementers once we have an agreed-upon set of restrictions.  The purpose is two-fold: 

   1. See how prevalent this problem is.  And

   2. let them know that they shouldn't be creating new tenants based on the restrictions outlined in https://folio-org.atlassian.net/browse/OKAPI-1081#icft=OKAPI-1081.

      1. Maybe we should have OKAPI reject new tenants based on these restrictions, but allow pre-existing tenants that are already in place.

3. Brainstorm what migrations would look like - what is the scope?  Stripes-config, edge API keys, etc. would all need to change.  What else is impacted?

Fortunately, Okapi does have some checks already. For example not allowing upper-case.