Add claims validation consistently

[SteveLasker]

          It could be argued this is essential to do, before merging this.

Originally posted by @OR13 in #183 (comment)

[OR13]

If we do validation, we should do it based on risk assessment.

• content type
• x5t, x5c

There needs to be an argument for "why" we added extra validation logic.

And we need to be sure that we do not overstep the validation and create interoperability issues

[yogeshbdeshpande]

We should prioritise what validation we need to do.
It is un-realistic to do validation of every element , however certain elements are essential to be validated!

Need to do analysis of which one are a priority and then proceed with a PR!

[OR13]

Lets leave claims validation to the callers, and reduce the code we must maintain.