add subtoken_capabilities

internal/db/dbModels/authcodeInfo.go

internal/db/dbModels/supertoken.go

internal/endpoints/token/super/pkg/authCodeFlowRequest.go

internal/endpoints/token/super/pkg/superTokenResponse.go

internal/oidc/authcode/authcode.go

internal/supertoken/capabilities/capability.go

internal/supertoken/pkg/supertoken.go