* added upper and lower case TA resolution testing
* added more detailed error reporting to the ValidateSignature method.
* extended test cases to test and verify these errs and their differences
* fixed CID attestation issue. CIDs are send in web compatible encoding that is not hex encoded and can be utilized without any further decoding on the server side.
* added checks and error handling for the Ta store object storage/loading
Signed-off-by: Jürgen Eckel <juergen@riddleandcode.com>