feat: default encryptAsync to v2

[bdesoky]

Ticket: WCN-723

This pull request updates the encryption in encryptAsync to default to v2

Encryption logic improvements:

• Changed the default encryption version in encryptAsync to v2 (Argon2id + AES-256-GCM), so unless explicitly set to v1, new data will use the more secure encryption scheme.

Testing enhancements:

• Updated unit tests to verify that v2 is the default and explicit v1 encryption still works.

[linear-code]

WCN-723

[bdesoky]

Synced with @pranavjain97, as this change doesnt remove the encrypt() function and no external callers are using encryptAsync, this change is not breaking. decryptAsync can handle v1/2 decryption with no changes