[code-coverage] Add tests for history decision task handler

[ketsiambaku]

What changed?
Introduced the following tests in service/history/decision:

• TestHandleDecisionRecordMarker

• TestHandleDecisionScheduleActivity

• TestHandleDecisionCancelWorkflow

Why?
improve code coverage in the package

How did you test it?
unit tests

Potential risks

Release notes

Documentation Changes

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 67.99%. Comparing base (edc5880) to head (22bfd07).
Report is 3 commits behind head on master.

Additional details and impacted files

see 11 files with indirect coverage changes

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[coveralls]

Pull Request Test Coverage Report for Build 018fabc6-df68-4d1a-b108-9517f6a6deb1

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 116 unchanged lines in 15 files lost coverage.
• Overall coverage increased (+0.02%) to 69.5%

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Files with Coverage Reduction	New Missed Lines	%
common/task/weighted_round_robin_task_scheduler.go	2	89.05%
service/matching/tasklist/task_list_manager.go	2	76.48%
common/persistence/sql/sqlplugin/mysql/task.go	2	73.68%
service/history/task/transfer_active_task_executor.go	2	72.72%
service/matching/tasklist/matcher.go	2	88.66%
service/history/task/fetcher.go	2	85.57%
common/persistence/sql/sqlplugin/mysql/db.go	2	79.49%
service/worker/scanner/executor/runq.go	3	85.48%
common/archiver/filestore/historyArchiver.go	4	80.95%
service/frontend/api/handler.go	6	62.2%

Totals
Change from base Build 018faadd-0f68-4f46-a937-a0c09b154ebd:	0.02%
Covered Lines:	102455
Relevant Lines:	147418

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💛 - Coveralls

[davidporter-id-au]

very fancy, easy to read though, nice!