NavigatorProvider: move the same-location check to the goTo function

[jsnajdr]

A tiny followup to #60561 that moves the new code to the goTo function. It maintains the structure of the reducer where all the work is done by the helper functions, and the reducer is just a command and control hub that assigns the work 🙂

[github-actions]

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Co-authored-by: jsnajdr <[email protected]>
Co-authored-by: youknowriad <[email protected]>

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[github-actions]

Flaky tests detected in aafbf89.
Some tests passed with failed attempts. The failures may not be related to this commit but are still reported for visibility. See the documentation for more information.

🔍 Workflow run URL: https://github.com/WordPress/gutenberg/actions/runs/8701563327
📝 Reported issues:

• [Flaky Test] should multi-select block with text selection and a block without text selection #59579 in /test/e2e/specs/editor/various/multi-block-selection.spec.js

[youknowriad]

This works for me.