NS1: code reorganization

[costasd]

This changeset splits the existing provider code into multiple files to enhance readability.

While there, fix also a couple minor tidbits observed during the split:

• Use the GetZone() that handles api timeouts in GetNameservers
• Merge a runaway capability to the rest of the capabilities

[tlimoncelli]

Very interesting!

Just the other day I was thinking that it would be useful to create a standard set of filenames to use for providers. I really like your name scheme.

The name scheme I had come up with was based on interfaces, not type of work. (see #3611 ).

I'd be interested in any feedback about what the new standard should be.

[costasd]

ah nice! Originally I was trying to do something more similar to #3611 - essentially splitting by the interfaces but it proved too complicated for a simple reorg, as the NS1 code doesn't separate concerns that clearly. So I went with something closer to what namedotcom, hexonet and gcore do instead - essentially splitting by the type of work.

Going back now, it seems more natural to me when implementing or reading a provider that you'll go and start implementing step-by-step: let's do the registrar, then the zones, then the records etc. No strong opinions though.

[tlimoncelli]

Yeah, I have no strong opinions here either. I do notice that some functions appear in 2 different interfaces, which makes my proposal not work as well. On the other hand, we could just document which place the function should appear.

[tlimoncelli]

After much consideration... I prefer your format. Merging.