Fix: Transit encrypt batch does not honor key_version

[rerorero]

Fix #10232

This PR fixes the bug where batch encrypt API doesn't work with key_version ( #10232).
Because HTTP server parses a JSON body as a map[string]interface with UseNumber(), logica.Request.Data can include json.Number instead of a primitive number.

This PR fixes the issue by allowing additional json.Number in path_encrypt. I didn't use such as FieldSchema out of respect for this work: #8775

I checked the following queries worked

$ curl --header "X-Vault-Token: dev" --request POST --data '{"batch_input":[{"key_version":1,"plaintext":"dGhlIHF1aWNrIGJyb3duIGZveA=="}]}' http://127.0.0.1:8200/v1/transit/encrypt/key1
{"request_id":"bfd9ae52-2e17-9fb7-24d3-77c52553cf8d","lease_id":"","renewable":false,"lease_duration":0,"data":{"batch_results":[{"ciphertext":"vault:v1:7YPcOIManbq2aW8Zwj1QlFzEM2+9BGyrC8Qu6QF0pRau/KcYiZK74AagVrp6hBs=","key_version":1}]},"wrap_info":null,"warnings":null,"auth":null}

$ curl --header "X-Vault-Token: dev" --request POST --data '{"key_version":1,"plaintext":"dGhlIHF1aWNrIGJyb3duIGZveA=="}' http://127.0.0.1:8200/v1/transit/encrypt/key1
{"request_id":"f786ad53-fcba-b24f-cf87-fab3ec1fecd0","lease_id":"","renewable":false,"lease_duration":0,"data":{"ciphertext":"vault:v1:j31QYZEnhsy8kdq1pM5nXflrFERTD3wY1t3OMUedhR/rRsxTkYuI9XmsH19UIp4=","key_version":1},"wrap_info":null,"warnings":null,"auth":null}

[sgmiller]

Thanks for the fix!