definitions: Deprecate Reacher and expire

[JinnyYi]

ref: #731

[codecov]

Codecov Report

Merging #734 (d155d2c) into master (56d461e) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #734   +/-   ##
=======================================
  Coverage   12.47%   12.47%           
=======================================
  Files          22       22           
  Lines        1483     1483           
=======================================
  Hits          185      185           
  Misses       1291     1291           
  Partials        7        7           

Flag	Coverage Δ
unittests	12.47% <ø> (ø)

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Impacted Files	Coverage Δ
tests/generated.go	2.22% <ø> (ø)
types/operation.generated.go	0.00% <ø> (ø)

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[Xuanwo]

Maybe we also need to deprecate expire?