A combination of using isset() instead of count() or strlen(), caching the
chunkify function, and replacing is_numeric() with some comparisons

When `mod_unique_id` is enabled the ID generated by it will be used for logging. This allows for correlation of the Apache logs and the ownCloud logs.

Testplan:

- [ ] When `mod_unique_id` is enabled the request ID equals the one generated by `mod_unique_id`.
- [ ] When `mod_unique_id` is not available the request ID is a 20 character long random string
- [ ] The generated Id is stable over the lifespan of one request

Changeset looks a little bit larger since I had to adjust every unit test using the HTTP\Request class for proper DI.

Fixes https://github.com/owncloud/core/issues/13366

This reverts commit 96a93192.

for password protected link shares the password is stored in shareWith, so we need to set this manually to null for the hooks

The URL was previously encoded twice which leads to getting redirected to a 404 page when the password has been entered incorrect at least once.

Testplan:

- [ ] Opening `http://localhost/core/index.php?redirect_url=%2Fcore%2Findex.php%2Fsettings%2Fadmin` redirects to the admin page when providing the correct credentials
- [ ] Opening `http://localhost/core/index.php?redirect_url=%2Fcore%2Findex.php%2Fsettings%2Fadmin` redirects to the admin page when providing the invalid credentials and then providing valid ones.
- [ ] Logging in as admin then going to the admin page and clearing the cookies and refreshing will show the login and when repeating the above test steps you're redirected correctly.

Fixes https://github.com/owncloud/core/issues/9804

Since the Storage interface isn't ready to work directly with exceptions
like Forbidden and NotFound, the DAV storage has been adapted to still
return false when expected.