brontide+peer: configurable read timeouts

[Crypt-iQ]

If a connection is slow, then it's possible for lnd's read deadlines to be hit. Ideally we should allow the user to raise these deadlines in case they have slow connections. This interacts with the issue outlined in #5837 since we may read the header just fine and then close the connection when trying to read the body.

Relevant call-sites:

• RecvActOne, RecvActTwo, RecvActThree in the brontide package
• when reading the init message:

  lnd/peer/brontide.go

  Line 577 in a28fbd4

  case <-time.After(handshakeTimeout):

• when calling ReadNextBody when peered with an implementation that doesn't use Nagle's algorithm to batch TCP packets:

  lnd/peer/brontide.go

  Line 1128 in a28fbd4

  rawMsg, readErr := noiseConn.ReadNextBody(buf[:pktLen])