removing "uri" format constraint from all string identifiers

[amotech-mdo]

as agreed in the meeting of the VDV 463 working group

[maikwoehl-psi]

Done with

• https://github.com/VDVde/VDV463/pull/15/commits/dab039c8a729a5e5e8744f5a21c96cc7e6e71daf
• https://github.com/VDVde/VDV463/pull/15/commits/c8ef320b50fe17026e0139d9e0aeb0c7296f48c9
• https://github.com/VDVde/VDV463/pull/15/commits/73c5f11ac736fe91f2c1f6854badbca4aac94129

directly on branch v1.1-dev