[QA] add tests for tag characters limit

[saw-jan]

ticket: https://github.com/owncloud/enterprise/issues/7180
Implemented in #11231

Define the maximum tag length. Defaults to 100 if not set. Set to 0 to not limit the tag length. Changes only impact the validation of new tags.

Default length: 100 chars
Available configs:

• OCIS_MAX_TAG_LENGTH

Open Task:
Add test scenarios for:

• create tag exceeding default limit -> should fail [full-ci] [tests-only] adding test for tag limit #11278
• create tag exceeding default limit with OCIS_MAX_TAG_LENGTH=0 -> should pass [full-ci] [tests-only] adding test for tag limit #11278
• create tag exceeding limit (OCIS_MAX_TAG_LENGTH=10) -> should fail [full-ci] [tests-only] adding test for tag limit #11278
• create tag under set limit (OCIS_MAX_TAG_LENGTH=10) -> should pass [full-ci] [tests-only] adding test for tag limit #11278

Also get test cases from these criteria:

Acceptance Criteria:

• Limit the maxium length of a tag in the input field (web)
• Use a configurable value coming from a capability (web)
• Implement the capability (server)
• Check the tag length also. Return 400 Bad Request when at least one tag is too long. (server)
• Limit the maximum amount of tags on a file (web)
• Use a configurable value coming from a capability (web)
• Implement the capability (server)
• Check the maximum amount of tags on a file also. Return 400 Bad Request when the amount of new tags would exceed the limit.