Update from update/networkservicemesh/sdk

[nsmbot]

Update go.mod and go.sum to latest version from networkservicemesh/sdk@main
PR link: networkservicemesh/sdk#1083
Commit: e4c4722
Author: Ed Warnicke
Date: 2021-10-13 16:51:05 -0500
Message:

• Rework client, connect, to simplify and prepare for simpler healing. (# 1083)

• Rework client, connect, to simplify and prepare for simpler healing.
  Previously we had a single 'client' per grpc.ClientConnInterface.
  This created a lot of complexity, particularly in connect.
  This rework of client moves to a single 'client' that can handle
  multiple grpc.ClientConnInterfaces.
  This vastly simplified both the client chain and connect chain.
  Finally, heal has been temporarily removed in preparation for a rework
  of heal focused on back propogating Connection 'DOWN' events via
  monitor. The net net at the end of the process should be:

1. Refresh is only originated by actual clients, not the 'client' part
   of passthrough NSEs
2. Heal will only be originated by actual clients, not the 'client' part
   pf passthrough NSEs.
   Signed-off-by: Ed Warnicke hagbard@gmail.com

• Response to comment Rework client, connect, to simplify and prepare for simpler healing. sdk#1083 discussion_r712830630
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Response to comment Rework client, connect, to simplify and prepare for simpler healing. sdk#1083 discussion_r712932273
  and also Rework client, connect, to simplify and prepare for simpler healing. sdk#1083 discussion_r712933068
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Response to comment Rework client, connect, to simplify and prepare for simpler healing. sdk#1083 discussion_r712936925
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Switch to dial per request
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Rebased and adapted to testing.
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Response to comment Rework client, connect, to simplify and prepare for simpler healing. sdk#1083 discussion_r717213643
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Response to comments.
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Fix golangci-lint errors.
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Fix to test goroutine leak checking.
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Response to comment Rework client, connect, to simplify and prepare for simpler healing. sdk#1083 discussion_r717225588
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Fix improper go routine leak checks in tests.
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Rework dial chain element to handle cleanup on close correctly.
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Restored grpc.WaitForReady in sandbox
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Response to comment https://github.com/networkservicemesh/sdk/pull/1083/files/4451e69ec246e30dde13a60d9f86efeb8a680766# r719022909
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Response to comment https://github.com/networkservicemesh/sdk/pull/1083/files/4451e69ec246e30dde13a60d9f86efeb8a680766# r719023399
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Response to Rework client, connect, to simplify and prepare for simpler healing. sdk#1083 discussion_r721014670
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Introducing monitor client chain element
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Response to comment Rework client, connect, to simplify and prepare for simpler healing. sdk#1083 discussion_r725789437
  Signed-off-by: Ed Warnicke hagbard@gmail.com
• Response to Rework client, connect, to simplify and prepare for simpler healing. sdk#1083 issuecomment-939699682