Fix applications page nested routes

[cstns]

Description

The applications create page was improperly nested causing the create form to be rendered at the bottom of the page instead of a new one.

Introduced by https://github.com/FlowFuse/flowfuse/pull/4744

Related Issue(s)

tbd

Checklist

• [x] I have read the contribution guidelines
• [ ] Suitable unit/system level tests have been added and they pass
• [ ] Documentation has been updated
  • [ ] Upgrade instructions
  • [ ] Configuration details
  • [ ] Concepts
• [ ] Changes flowforge.yml?
  • [ ] Issue/PR raised on FlowFuse/helm to update ConfigMap Template
  • [ ] Issue/PR raised on FlowFuse/CloudProject to update values for Staging/Production

Labels

• [ ] Includes a DB migration? -> add the area:migration label

[knolleary]

Verified locally. Merge when tests pass.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 78.79%. Comparing base (9e7b1e4) to head (c144a18). Report is 2 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #4765 +/- ## ======================================= Coverage 78.79% 78.79% ======================================= Files 311 311 Lines 14781 14781 Branches 3384 3384 ======================================= Hits 11646 11646 Misses 3135 3135 ``` | [Flag](https://app.codecov.io/gh/FlowFuse/flowfuse/pull/4765/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=FlowFuse) | Coverage Δ | | |---|---|---| | [backend](https://app.codecov.io/gh/FlowFuse/flowfuse/pull/4765/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=FlowFuse) | `78.79% <ø> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=FlowFuse#carryforward-flags-in-the-pull-request-comment) to find out more.

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