* Standardized header ordering for C++ repo
* Reordered categories to move private headers above public headers; added space between categories to enable future flexibility
* Split out attestation client factory into separate class
* Updated readme; clang-format
* Final set of API review changes
* Replaced () constructors with {} constructors
* Moved samples around to meet new recommendations; added a couple of additional tests.
* Reworked attestation to include RetrieveAttestationValidationCollateral
* Attestation sample readme updates
* TPM doesn't need to retrieve response validation collateral
* Added cautionary warning about the dangers of overriding the TearDown method from inside a test case
* Added attestation team members to codeowners for attestation SDK
* Remove CODEOWNERS from cspell checks
* Don't hold a lock across retrieving the signers over the network
* Updated snippets in readme; clang-format
* Added GetPolicyManagementCertificates
* Added Add and Remove policy certificate
* Added support for Tpm attestation
* Moved TPM to attestation service specific section
* Added support for validation callback
* Updated RequestFailedException documentation
* SetPolicy and ResetPolicy APIs
* Added tests for attestation result; cleaned up attest test suite a bit; fixed up attestation sample to be more real
* Further refactored test collateral to reduce wasted test cases
* Reformat with clang-format-11
* Removed use of Nullable::HasValue() and Nullable::Value() in favor of operator bool and operator *
* Get policy sample to run in CI pipeline
* Added AZURE_ variables to test-resources.json
