Enable an option to switch b/w NHCX and Open HCX

[khavinshankar]

• Add an environment variable to decide the flavor of HCX used.
• Add a utility class for each flavor of HCX which should handle encrypting and decrypting data, generating login tokens, and other setup-related functions.

[khavinshankar]

Instead of switching b/w the HCX flavor, we should be enabling the usage of multiple flavors (Open HCX and NHCX) at the same time. It should be decided based on the payer ID.