MAINT: Simplify interface execution and better error handling of Node

[oesteban]

Revises the implementation of Node simplifying some details and improves the error handling of plugins. Introduces a NodeExecutionError (custom alias of RuntimeError) that allows more specificity with errors, if needed.

Requires: #3347.

Summary

Fixes # .

List of changes proposed in this PR (pull-request)

Acknowledgment

• (Mandatory) I acknowledge that this contribution will be available under the Apache 2 license.

[codecov]

Codecov Report

Merging #3349 (c0f49c7) into master (bb125ab) will increase coverage by 0.89%.
The diff coverage is 81.39%.

❗ Current head c0f49c7 differs from pull request most recent head bbcd4ff. Consider uploading reports for the commit bbcd4ff to get more accurate results

@@ Coverage Diff @@ ## master #3349 +/- ## ========================================== + Coverage 64.23% 65.13% +0.89%  ========================================== Files 307 307 Lines 40373 40364 -9 Branches 5326 5333 +7 ========================================== + Hits 25935 26290 +355  + Misses 13385 13005 -380  - Partials 1053 1069 +16 

Flag	Coverage Δ
unittests	64.85% <81.39%> (?)

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
nipype/pipeline/plugins/tools.py	76.00% <ø> (-0.32%)	⬇️
nipype/pipeline/plugins/base.py	58.15% <50.00%> (-0.02%)	⬇️
nipype/interfaces/matlab.py	78.02% <66.66%> (+4.02%)	⬆️
nipype/pipeline/engine/nodes.py	78.93% <84.21%> (+1.56%)	⬆️
nipype/interfaces/base/core.py	87.95% <100.00%> (-0.23%)	⬇️
nipype/interfaces/base/support.py	82.19% <100.00%> (+1.26%)	⬆️
nipype/pipeline/plugins/linear.py	90.69% <100.00%> (+12.12%)	⬆️
nipype/interfaces/ants/registration.py	73.09% <0.00%> (ø)
nipype/interfaces/spm/preprocess.py	50.44% <0.00%> (+0.88%)	⬆️
... and 19 more

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[effigies]

@oesteban Rebase to clean up the diff?

[effigies]

@oesteban Rebased on your behalf.

[effigies]

Overall I think it looks good. A couple initial thoughts, and please bug me to do another review.

[effigies]

LGTM. Suggested updating the linear to have the same exception behavior as distributed, but don't feel very strongly.

[effigies]

Failing test fixed in #3378. Merging.