Consider removing wt.datagrams.writable

[jan-ivar]

No description provided.

[martenrichter]

And what would be the replacement? A single sending method?
Would readable also be replaced? ( I am just curious, as I want to keep the interface up to date).

[jan-ivar]

Sorry I created this in a meeting with insufficient description. This would be after #620 is merged.

There would still be a single readable for incoming datagrams.

[vasilvv]

I feel like it's worth keeping the default writable, since most applications would only need one.

[jan-ivar]

Meeting:

• leaning toward keeping.
• what should the default sendOrder for wt.datagrams.writable be? 1 or max int?
• If you don't want the wt.datagrams.writable to starve everything else you need to put stuff in a different send group.