Fix userinfo retriaval with post call

[bhagyasakalanka]

Purpose

Currently, the userinfo endpoint fails to give response with POST calls if the contentType header is not present in the request. But in lower versions, we support this behavior. With this fix, we bring the expected behavior

Fix explain

1. Bring back the behavior before Issue[1]/PR[1] which is to validate the content type at code level instead on using @consumer annotation.
2. Remove the fix done in Issue[2]/PR[2] as POST body token resolving was already available in step 1 solution.
3. Prevent allowing passing token in the body of a GET request.
4. Bring removed unit tests in PR[1]. Improve the tests to work with newer versions.

We could bring the behavior before Issue[1]/PR[1] because the said issue in the Issue[1] is resolved in RequestCorrelationIdValve and the request body is passed to userinfo endpoint level.

Related Issues

• [1] Sending access_token through /oauth2/userinfo API Body in WSO2 5.7.0 wso2/product-is#4403
• [2]chttps://github.com/Sending access token through request body to oauth2/userinfo wso2/product-is#10387

Related PRs

• [1] Fix #4403:Sending access_token through /oauth2/userinfo API Body in WSO2 5.7.0 #1065
• [2] Sending access token through request body to oauth2/userinfo #1535

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Approving the pull request based on the successful pr build https://github.com/wso2/product-is/actions/runs/10387037657