Reader profile - fix the id fallback case of the username route.

[Addison-Stavlo]

Related to # #100098 (comment) and introduced from #100096

Proposed Changes

Fixes a bug where the /reader/users/{username||id-fallback} route wasnt properly rendering with the id fallback.

• Updates the action dispatch for the user data to continue using what it did before this when we are not specifically requesting by ID.

Why are these changes being made?

• I done made more regressions 🙈

Testing Instructions

• Test the user profile as much as you can to make sure it works.
• Try `/reader/users/{username||id-fallback}, both with your username and ID, make sure they both work.
• Make sure /reader/users/id/{userId} continues to work as expected.
• Test unfindable values in all of the above (non existant usernames and ids).
• Test the lists tab.
• Test anything else you can think of around user profile.

Pre-merge Checklist

• Has the general commit checklist been followed? (PCYsg-hS-p2)
• Have you written new tests for your changes?
• Have you tested the feature in Simple (P9HQHe-k8-p2), Atomic (P9HQHe-jW-p2), and self-hosted Jetpack sites (PCYsg-g6b-p2)?
• Have you checked for TypeScript, React or other console errors?
• Have you used memoizing on expensive computations? More info in Memoizing with create-selector and Using memoizing selectors and Our Approach to Data
• Have we added the "[Status] String Freeze" label as soon as any new strings were ready for translation (p4TIVU-5Jq-p2)?
  • For UI changes, have we tested the change in various languages (for example, ES, PT, FR, or DE)? The length of text and words vary significantly between languages.
• For changes affecting Jetpack: Have we added the "[Status] Needs Privacy Updates" label if this pull request changes what data or activity we track or use (p4TIVU-aUh-p2)?

[github-actions]

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https://calypso.live?image=registry.a8c.com/calypso/app:build-134153

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https://calypso.live?image=registry.a8c.com/calypso/app:build-134153&env=jetpack

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https://calypso.live?image=registry.a8c.com/calypso/app:build-134153&env=a8c-for-agencies

[matticbot]

This PR does not affect the size of JS and CSS bundles shipped to the user's browser.

Generated by performance advisor bot at iscalypsofastyet.com.

[artemiomorales]

Works for me!