Make ExecutorPickle add RemovedNodeCause

[jglick]

Downstream of jenkinsci/workflow-cps-plugin#473. Further refines #175 to use a specific CauseOfInterruption introduced in #104 for a related reason.

Before:

Resuming build at … after Jenkins restart
Waiting to resume part of p #1: ‘Jenkins’ doesn’t have label ‘slave0’
Waiting to resume part of p #1: ‘Jenkins’ doesn’t have label ‘slave0’
Waiting to resume part of p #1: ‘Jenkins’ doesn’t have label ‘slave0’
Waiting to resume part of p #1: ‘Jenkins’ doesn’t have label ‘slave0’
Waiting to resume part of p #1: ‘Jenkins’ doesn’t have label ‘slave0’
[Pipeline] End of Pipeline
ERROR: Killed part of p #1 after waiting for 15,000 ms because we assume unknown Node slave0 is never going to appear!
Finished: FAILURE

After:

Resuming build at … after Jenkins restart
Waiting to resume part of p #1: ‘Jenkins’ doesn’t have label ‘slave0’
Waiting to resume part of p #1: ‘Jenkins’ doesn’t have label ‘slave0’
Waiting to resume part of p #1: ‘Jenkins’ doesn’t have label ‘slave0’
Waiting to resume part of p #1: ‘Jenkins’ doesn’t have label ‘slave0’
Waiting to resume part of p #1: ‘Jenkins’ doesn’t have label ‘slave0’
Killed part of p #1 after waiting for 15 sec because we assume unknown agent slave0 is never going to appear
[Pipeline] End of Pipeline
Agent was removed
Finished: ABORTED