New street > Start with a copy of last street creates invalid URL

[kfarr]

Describe the bug
As a user trying to "remix" an existing street from another user by I want the new street URL to be valid.

To Reproduce
Steps to reproduce the behavior:

1. Go to any public street of another user while you are logged in
2. Click on New Street
3. Then click Start with a copy of last street
4. See error in URL bar -- the URL username is the old user, but the street ID is correct

For example if I remix this street: https://streetmix.net/tomasborja21/1/university-blvd using New > Copy from last then I will see a URL such as https://streetmix.net/tomasborja21/100 instead of https://streetmix.net/myusername/100

This causes issues such as:

• when sharing the URL or reloading the page that URL results in 404
• when exporting to 3dstreet the URL is invalid and the street does not load

Expected behavior
I should see https://streetmix.net/my_username/new_street_id/street_slug instead of https://streetmix.net/other_username/new_street_id/street_slug

Screenshots
https://github.com/streetmix/streetmix/assets/470477/e0d446af-54e8-4d1f-bc08-0121d6431208

Desktop (please complete the following information):

• OS: Mac OS
• Browser Chrome
• Version Latest