`getStringList` should throw a `TypeError` if the stored value is of a
different type, but the recent change to use JSON-encoded string lists
regression that behavior if the stored type was a string, causing it to
instead return null.

This restores the previous behavior by passing extra information from
Kotlin to Dart when attempting to get an enecoded string list, so that
if a non-encoded-list string is found, a TypeError can be created on the
Dart side.

Since extra information is now being passed, the case of a
legacy-encoded value is now communicated as well, so that we only have
to request the legacy value if it's there, rather than always trying
(which was not worth the complexity of adding extra data just for that
initially, but now that we need extra data anyway, it's easy to
distinguish that case).

Fixes OOB regression in `shared_preferences` tests that has closed the
tree.

Speculatively fixes flutter/flutter#155433. Read [one of my later comments](flutter/flutter#155433 (comment)) on that thread for my current understanding of this issue. In summary, this PR rewrites `_readFQDN` to avoid recursion.

**For reviewers: For a simplified diff, see the first commit, [change](https://github.com/flutter/packages/commit/7afa1db54e07f024b2a4550d160b4d4a9f67f2c7).** This commit avoids formatting make sure the diff only highlights changes to logic rather than formatting.

<details>

<summary> Pre-launch Checklist </summary>

- x ] I signed the [CLA].

</details>

This PR is a subset of #8237 - it only adds platform interface changes.

Partially resolves [86613](flutter/flutter#86613).

fixes：flutter/flutter#161305 
also fix some typos: statefull* -> stateful*

…xyApi` from pigeon (#8311)

Also fixes flutter/flutter#152352

Reverts #8494

This is a revert in order to reland (as a revert of this revert) now that the out-of-band failure in shared preferences is resolved, so that the package can go through the CI release process to ensure that the new tooling for pre-publish builds is working correctly.