Em174 Add FPX source type to omise swift

[tookaa2]

1. Objective

Currently FPX is awaiting to go live, we want to update the libraries to support this new source type so the dashboard app can display FPX in charge list correctly.

2. Description of change

• Added FPX source type along with 19 banks that are available as source[bank] option
• Added test cases for charge creation and retrieval for FPX

3. Quality assurance

Run tests and make sure the newly added test for FPX passes

4. Operations impact N/A

5. Business impact N/A

6. The priority of change Normal

[tobias90]

@tookaa2 Can you please also add the new payment method to the capability-get.json and run the CapabilityOperationFixtureTests?