docs(TransferStateService): consistent semi-colons, adjust wording of getState() description

[kananlanginhooper]

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• Tests for the changes have been added (for bug fixes / features)
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What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
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  Documentation

What is the current behavior?

Issue Number: N/A

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Does this PR introduce a breaking change?

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