Reapply Site Migration: Default to hiding the migration trial from unverified users

[markbiek]

NOTE: We first attempted this in #90589 and ran into weird pre-release test failures. I manually ran the pre-release tests on this PR and they passed so I'll try deploying again on Mon.

Proposed Changes

We've decided to default to hiding the migration free trial from unverified users across all migration flows. This behavior can be overridden by passing the data parameter to navigate.

Testing Instructions

• As a logged in a verified user, go to /start.

• Proceed through the migration flow.

• On the Upgrade Plan step, verify that you have the option for a 7-day trial.

• As a new, unverified user, go to /start.

• Proceed through the migration flow.

• On the Upgrade Plan step, verify that you do not have the option for a 7-day trial. You should only see "Upgrade and migrate"/

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 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]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-107452

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-107452&env=jetpack

Automattic for Agencies live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-107452&env=a8c-for-agencies

[matticbot]

Here is how your PR affects size of JS and CSS bundles shipped to the user's browser:

Sections (~1 bytes removed 📉 [gzipped])

name              parsed_size           gzip_size
migration-signup        -47 B  (-0.1%)       -1 B  (-0.0%)

Sections contain code specific for a given set of routes. Is downloaded and parsed only when a particular route is navigated to.

Legend

What is parsed and gzip size?

Parsed Size: Uncompressed size of the JS and CSS files. This much code needs to be parsed and stored in memory.
Gzip Size: Compressed size of the JS and CSS files. This much data needs to be downloaded over network.

Generated by performance advisor bot at iscalypsofastyet.com.

[sixhours]

LGTM!