Changes to Create OS user and register as tenant

the display_name request property's minLength was increased from 0 to 1

the password request property's minLength was increased from 0 to 12

added the pattern ^[a-z][a-z0-9_-]{1,30}[a-z0-9]$ to the request property username

the display_name request property's maxLength was set to 100

the password request property's maxLength was set to 128

added the new optional request property dry_run

added the new optional request property gateway_port

added the new optional request property owner_gateway

added the non-success response with the status 429

endpoint added