Add a custom URL type instead of rely on httpx.URL

[vdusek]

• We use the httpx.URL in the ProxyConfiguration.
• It kind of shot us into the foot in Unable to use proxy with port 80 or 443 with Playwright #618.
• I suggest replacing it with our custom data type (either the Pydantic model or data class).
• Also please find other occurrences of the httpx.URL in the Crawlee and replace them with our custom type.

[janbuchar]

A Pydantic type wouldn't probably help us much, those are typically just for validation/serialization.

[vdusek]

This new type could potentially be used more widely throughout the project, including in the Request model. It could also offer setters for managing query parameters and other attributes. Additionally, it might replace some of our existing URL-related helpers in _utils/urls.py and parts of _utils/requests.py, such as the URL normalization.

[janbuchar]

We might also want to use something like https://github.com/aio-libs/yarl