Add URL path to client URL in in Client._parse_host()

[bplunkert]

This fix for #113 allows instantiating a client with a custom URL path as part of the host argument.

[HorseCheng]

Someone please approve the PR and merge the code. 🥺

ChatOllama uses this library, which has an issue that needs to be addressed as well. The sample code below shows that the URL path "copilot" is not passed in:

from langchain_ollama import ChatOllama

chat_model = ChatOllama(
    model="llama3.1",
    base_url = "https://aaaaaaaaaaa.com/copilot"
)

chat_model.invoke("hello")

[jason-heo]

Resolves #244 as well.

I'd love to see this PR get merged.

[bplunkert]

thanks @mxyng I've added your suggestions to the pull request.