Added missing Tailwind CSS and jQuery validation assets

[saciervo]

Ensure Identity UI loads its styles and client-side validation scripts so the pages look right and validate smoothly.

Issue:
The Identity Account Manage page (/Identity/Account/Manage) fails to load properly because required static files are missing from the template.

Downloaded jQuery Validation Scripts:
They are required by _ValidationScriptsPartial.cshtml, so I downloaded them to wwwroot/Identity/lib/:

• https://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.17.0/jquery.validate.js
• https://cdnjs.cloudflare.com/ajax/libs/jquery-validation-unobtrusive/3.2.11/jquery.validate.unobtrusive.js

Built the CSS:
Run ./tailwindcss.exe -i ./tailwind.input.css -o ./wwwroot/css/app.css --minify (or use npx tailwindcss on non-Windows)

Before:

After:

[mythz]

Thanks for the PR, except no static files should be added to wwwroot which is an ignored directory since it gets replaced when building production, instead all static files should be added to MyApp.Client/public/lib which gets copied to ./wwwroot as part of the build which I've done in this commit:

59a012d