fix: update test mode and payments method enabled in payments connector

[Sangamesh26]

Type of Change

• [x] Bugfix

Description

1> Test mode was not getting updated in payments connector update, it is handled now 2> when Payments_method_enabled was not passed in update call, it used to not show up the earlier payments_method_enabled, it is handled now 3> If payments_method_enabled is passed, then in the retrieve call, it used to show up the both earlier payments_method_enabled as well as present payments_method_enabled instead of just showing up the updated payments_method_enabled, it is handled now.

Motivation and Context

Payments connector update and retrieve call proper working

How did you test it?

Manual

Checklist

• [x] I formatted the code cargo +nightly fmt --all
• [x] I addressed lints thrown by cargo clippy
• [x] I reviewed submitted code