fix(core): create completed field on settlement for better tracking

[jmcdo29]

PR Type

Please check if your PR fulfills the following requirements:

• The commit message follows our guidelines: https://github.com/nestjs/nest/blob/master/CONTRIBUTING.md
• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior?

Currently, even correct circular dependencies can cause exceptions for seemingly no reason.

Issue Number: #12153

What is the new behavior?

With this new completed field, all properly managed circular dependencies work as anticipated.

Does this PR introduce a breaking change?

• Yes
• No

Other information

[coveralls]

Pull Request Test Coverage Report for Build eab18eac-4ef9-4c02-a47d-31efd45ba489

• 3 of 4 (75.0%) changed or added relevant lines in 1 file are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.01%) to 92.801%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
packages/core/injector/settlement-signal.ts	3	4	75.0%

Files with Coverage Reduction	New Missed Lines	%
packages/core/injector/settlement-signal.ts	1	78.57%

Totals
Change from base Build de330e86-7c2b-484a-b17f-f872998b5610:	-0.01%
Covered Lines:	6394
Relevant Lines:	6890

---

💛 - Coveralls

[kamilmysliwiec]

lgtm