[PRP-335] Change /count routing to allow navigating back

[rocketnova]

Ticket

https://wicmtdp.atlassian.net/browse/PRP-335

Changes

What was added, updated, or removed in this PR.

• Change /count behavior. If participant data has been entered:
  • Disable the householdSize field
  • Display an Alert
  • Allow navigating back to /count
  • Allow navigating forward from /count if the householdSize field is disabled
• Add a disabled prop to the <TextField> component
• Add a count attribute to the SubmissionData type

Context for reviewers

Testing instructions, background context, more in-depth details of the implementation, and anything else you'd like to call out or ask reviewers. Explain how the changes were verified.

Right now our routing safeguards prevent users from going back to /count after they’ve filled out /details, and send them to the next unfilled out page, such as /changes. This is correct if someone is using the url bar to navigate directly to /count, but if they are using the back button, this creates confusing behavior.

Testing

Screenshots, GIF demos, code examples or output to help show the changes working as expected. ProTip: you can drag and drop or paste images into this textbox.

[github-actions[bot]]

Chromatic_Build : Link to latest build in Chromatic 🌈 Link to storybook build in Chromatic