[CLI] replace BackgroundContext with CLI's context

[shijiesheng]

What changed?
Instead of using background context. Use CLI's provided context.

Why?

New CLI framework allows passing a root context from app.RunContext. We want to follow this practice to simplify things like jwt / opentracing propagation.

How did you test it?

unit test

Potential risks

Release notes

Documentation Changes

[codecov]

Codecov Report

Attention: Patch coverage is 30.00000% with 7 lines in your changes missing coverage. Please review.

Project coverage is 73.61%. Comparing base (d4884cc) to head (825f23b).
Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
tools/cli/admin_elastic_search_commands.go	0.00%	4 Missing ⚠️
tools/cli/admin_db_scan_command.go	0.00%	1 Missing ⚠️
tools/cli/admin_kafka_commands.go	0.00%	1 Missing ⚠️
tools/cli/admin_timers.go	0.00%	1 Missing ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
tools/cli/utils.go	55.98% <100.00%> (ø)
tools/cli/workflow_commands.go	37.43% <100.00%> (ø)
tools/cli/admin_db_scan_command.go	0.00% <0.00%> (ø)
tools/cli/admin_kafka_commands.go	0.00% <0.00%> (ø)
tools/cli/admin_timers.go	0.00% <0.00%> (ø)
tools/cli/admin_elastic_search_commands.go	0.00% <0.00%> (ø)

... and 4 files with indirect coverage changes

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