[FEATURE] usage of JWKS with JWT (without using OpenID connect)

[Rishav9852Kumar]

Description :
An enhancemenet of usage of JWKS with JWT (w/o OpenID connect)
to enable de-coupling between HTTPJwtAuthenticator and HTTPJwtKeyByOpenIdConnectAuthenticator
So this usage of JWKS with JWT could be extended to the JWT backend instaed of OIDC auth backend

What solution would you like?
Extending auth with jwks_uri parameter in JWTs Configuring (inseted of depending on openid in HTTPJwtKeyByOpenIdConnectAuthenticator)

What alternatives have you considered?
#2808

Do you have any additional context?
#2708 (comment) (Moving JWKS completely inside HTTPJwtAuthenticator)

[cwperks]

Thank you for filing this issue @Rishav9852Kumar. For anyone coming across this issue, this is currently possible using the openid backend as outlined in the documentation here: https://opensearch.org/docs/latest/security/authentication-backends/jwt/#using-a-jwks-endpoint-to-validate-a-jwt

This issue is about supporting it directly in the jwt backend as requested in #1858 (comment)