Add read/write timeout options for Typha connection.

[fasaxc]

Description

Fixes #1537

Todos

• Move pin back to projectcalico/typha repo once fix is merged to client.
• Release note
• Docs

Release Note

Fix that, in some cases, Felix wouldn't spot if it got disconnected from Typha (#1537)

[caseydavenport]

Looks fine to me.

My only question is how did we decide on the default values - 30s / 10s.

They seem sensible enough though.

[fasaxc]

The read timeout is set to 3x the default Typha ping interval; I figure missing 3 pings (with no other traffic) is a pretty bad sign.

I don't have much to back up the choice of write timeout, except that it matches the existing connection timeout. I really don't expect writes to take very long at all since we only write a packet every 10s to respond to pings.