Fill domainID for backwards compatibility

[vytautas-karpavicius]

What changed?
Added fallback to set domainID based on domainName for pending child executions when loading mutable state.

Why?
With #4601 newly introduced DomainID may not be set for older workflows.
Here we will fill its value based on previously used domain name.

Trying to store such mutable state to cassandra, it fails with error Invalid UUID ""

How did you test it?
Added unit test.

Potential risks

Release notes

Documentation Changes

[coveralls]

Pull Request Test Coverage Report for Build 3a3d09d0-4af8-43f1-a61b-212a94d181e0

• 10 of 12 (83.33%) changed or added relevant lines in 1 file are covered.
• 46 unchanged lines in 6 files lost coverage.
• Overall coverage increased (+0.008%) to 56.963%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
service/history/execution/mutable_state_builder.go	10	12	83.33%

Files with Coverage Reduction	New Missed Lines	%
common/membership/hashring.go	2	83.54%
service/matching/taskListManager.go	2	73.77%
service/history/task/fetcher.go	3	86.67%
common/persistence/nosql/nosqlExecutionStore.go	9	60.03%
common/persistence/nosql/nosqlplugin/cassandra/tasks.go	14	72.8%
common/persistence/nosql/nosqlTaskStore.go	16	58.37%

Totals
Change from base Build 8d87d80f-afd1-43e9-ba9d-8f82a47525d8:	0.008%
Covered Lines:	84000
Relevant Lines:	147464

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💛 - Coveralls