new header X-Access-Token should be used

Current Situation

Almost all web services of JOC Cockpit needs the header field access_token.
The name of this header is not conform with RFC.
In particular, the underscore can make problems.

Desired Behavior

• JOC Cockpit GUI should request with the new header X-Access-Token in addition with the same value like access_token.
• The already used header access_token retain unchanged for compatibility.
• The ./login web service should have X-Access-Token in the response headers.
• All other web services should read the new header X-Access-Token to get the access token.