cli: use configured endpoint for proxy lookup

[Sakshamm-Goyal]

- What I did

Use the configured Docker endpoint, rather than a connection helper's internal HTTP placeholder, when selecting per-daemon proxy configuration for container create/run and image build.

Fixes #5797.

- How I did it

Added a shared daemon-host resolver that prefers the original endpoint and falls back to the API client's host for test and compatibility paths. Added a regression covering an SSH endpoint whose API client uses http://docker.example.com internally.

- How to verify it

TZ=UTC ./scripts/with-go-mod.sh go test ./cli/command ./cli/command/container ./cli/command/image -count=1

Configure distinct default and ssh://daemon.example.com entries under proxies, then create or run a container through that SSH context. The container receives the SSH endpoint's proxy values.

- Human readable description for the release notes

Use per-daemon proxy configuration for SSH Docker contexts.

- A picture of a cute animal (not mandatory but encouraged)

Not included.