Move WC_GoCardless class to its own file

[leonardola]

Description

I would be nice to have a separate file for the WC_GoCardless class instead of using the main plugin file for it.

[ravinderk]

@leonardola I notices that this file has logic to do following:

• loading files
• running migration to upgrade to newer version: https://github.com/woocommerce/woocommerce-gateway-gocardless/blob/trunk/woocommerce-gateway-gocardless.php#L242
• register hpos compatibility
• handle gocarless payment status change and webhook: https://github.com/woocommerce/woocommerce-gateway-gocardless/blob/trunk/woocommerce-gateway-gocardless.php#L102#L103
• Register plugin links
• Fewer helper functions like: log https://github.com/woocommerce/woocommerce-gateway-gocardless/blob/trunk/woocommerce-gateway-gocardless.php#L353

I think main plugin file should only bootstrap plugin. I did not see need of refactoring this file at this moment or benifit.
I think we should stop adding code to this files except if we are loading a new file.

Let me know if you have any question or you want me to implement refactoring for above list except loading files logic.

[dkotter]

I think main plugin file should only bootstrap plugin.

I do agree with this in most cases, though looking at various other Woo extensions, there doesn't seem to be a consistent approach. Some have a class in the main plugin file like this extension, others don't but still have lots of functionality in the main plugin file. Doesn't mean we can't/shouldn't clean this extension up though.

I did not see need of refactoring this file at this moment or benefit.

@ravinderk Just to be clear, you're suggesting we hold off on doing any sort of refactoring at the moment, correct? If so, I think that's fine though I would like to keep this item in our backlog and we can look to tackle this if we don't have any higher priority items.

[ravinderk]

I think main plugin file should only bootstrap plugin.

I do agree with this in most cases, though looking at various other Woo extensions, there doesn't seem to be a consistent approach. Some have a class in the main plugin file like this extension, others don't but still have lots of functionality in the main plugin file. Doesn't mean we can't/shouldn't clean this extension up though.

I did not see need of refactoring this file at this moment or benefit.

@ravinderk Just to be clear, you're suggesting we hold off on doing any sort of refactoring at the moment, correct? If so, I think that's fine though I would like to keep this item in our backlog and we can look to tackle this if we don't have any higher priority items.

@dkotter Yes, I am suggesting to hold off at this moment.

[leonardola]

I'm ok with holding off. That's why it's low priority. It's something we should aim but not something we need to do now.