HS ticket #1522768 - Fix to issue: Appeal doesn't display if user preferences is not set or invalid

[zweatshirt]

Description

• When selecting an appeal, setViewMode in AppealsWrapper.tsx is never called unless the user already has a preference set. This leads to a completely blank screen that is confusing for users.
• This solution fixes the issue by having a setting the fallback back view mode to Flows, and it does not modify user preferences.
• This issue also affects new users, and this PR fixes the issue for new users.

NOTE: There seems to be a deeper underlying issue for the particular user in the HS ticket, where their preference may have been set to an invalid value at some point in the application, or their preference was not being persisted by the API. They are not a new user, and so this issue should have never occurred.

HelpScout ticket

Testing

• Go to Tools > Appeals
• Create an Appeal
• Check that behavior works as expected if the user's preferences are set from the API, and if they are not set. The default Flows view should show if the user doesn't already have a preference. You can test this by going to Contacts and setting the view to List
• For testing a user with no preferences yet (or potentially invalid values) to recreate the bug, you can create a new account, or wipe the preferences data for the test account in the staging API console.

Checklist:

• I have given my PR a title with the format "MPDX-(JIRA#) (summary sentence max 80 chars)"
• I have applied the appropriate labels (Add the label "Preview" to automatically create a preview environment)
• I have run the Claude Code /pr-review command locally and fixed any relevant suggestions
• I have requested a review from another person on the project
• I have tested my changes in preview or in staging
• I have cleaned up my commit history

[github-actions]

Preview branch generated at https://HS-1522768.d3dytjb8adxkk5.amplifyapp.com

[github-actions]

Bundle sizes [mpdx-react]

Compared against cfa6ff2

No significant changes found