Replace spaces with - in a newly created repo name and display how it will look like

[redve-dev]

Implemented quality-of-life feature known from Github

In the current state when user attempts to create repository with space in name, he gets an error.
With this template changes, the repository is created with dashes in place of spaces. The dashes can be changed by editing line "const char_in_repo_name = '-'", which can be easily moved to the config in the future. Moreover user gets live-preview of the repo name while creating repo.

[yardenshoham]

Don't put style and script tags in HTML templates

[silverwind]

Yes, put that stuff in web_src/css and web_src/js. The only valid reason for inline CSS/JS is for render-critical code, this is not such code.

[silverwind]

Regarding the feature itself, it needs to handle more than just spaces, in fact on GitHub, every invalid character is replaced, and it also applies to org creation (where github seems to have a slightly different algorithm as it does not add the trailing -, but I'd use the org algo):

This is something that should have some unit tests which will are also easy to write, just a function that takes a string and returns a string.

IIRC, Gitea allows more special characters then GitHub, so that will likely need to be taken into account.

[wxiaoguang]

Thank you for your PR, since this PR has been inactive for long time, I made a simple one: Fix some migration and repo name problems #33986