DISPATCH-2338 - dockerfiles: Introduce Debian-based slim image w/ CI tests (#1550)

* NO-JIRA: dockerfiles: Introduce Debian-based slim image

Use Debian stable release slim image with multistage build to
keep image size reasonable (143MB compared to 1.39GB Ubuntu based image).

Other changes compared to Ubuntu based image:
* libuv is enabled
* a bit more careful work with dependencies
* allow building web console
* faster builds with Ninja
* build from release, not master; configurable
* other minor changes in build process, etc

Signed-off-by: Ievgen Popovych <ievgenp@seetrue.ai>

* dockerfiles: debian: use epoll, cosmetics, include ca-certificates

* dockerfiles: debian: Clone from Github

* dockerfiles: debian: Make sure /usr/share/qpid-dispatch exists

..to fix build with disabled web console.

* dockerfiles: debian: Build from checked out source code

* NO-JIRA: [GHA] Build Debian image

* dockerfiles: debian: Install npm only if required (on build stage)

* NO-JIRA: Add dockerignore
3 files changed