* Transit: Support batch encryption
* Address review feedback
* Make the normal flow go through as a batch request
* Transit: Error out if encryption fails during batch processing
* Transit: Infer the 'derived' parameter based on 'context' being set
* Transit: Batch encryption doc updates
* Transit: Return a JSON string instead of []byte
* Transit: Add batch encryption tests
* Remove plaintext empty check
* Added tests for batch encryption, more coming..
* Added more batch encryption tests
* Check for base64 decoding of plaintext before encrypting
* Transit: Support batch decryption
* Transit: Added tests for batch decryption
* Transit: Doc update for batch decryption
* Transit: Sync the path-help and website docs for decrypt endpoint
* Add batch processing for rewrap
* transit: input validation for context
* transit: add rewrap batch option to docs
* Remove unnecessary variables from test
* transit: Added tests for rewrap use cases
* Address review feedback
* Address review feedback
* Address review feedback
* transit: move input checking out of critical path
* transit: allow empty plaintexts for batch encryption
* transit: use common structs for batch processing
* transit: avoid duplicate creation of structs; add omitempty to response structs
* transit: address review feedback
* transit: fix tests
* address review feedback
* transit: fix tests
* transit: rewrap encrypt user error should not error out
* transit: error out for internal errors
This ensures that we can safely rotate and modify configuration
parameters with multiple requests in flight.
As a side effect we also get a cache, which should provide a nice
speedup since we don't need to decrypt/deserialize constantly, which
would happen even with the physical LRU.
* Remove raw endpoint from transit
* Add multi-key structure
* Add enable, disable, rewrap, and rotate functionality
* Upgrade functionality, and record creation time of keys in metadata. Add flag in config function to control the minimum decryption version, and enforce that in the decrypt function
* Unit tests for everything
