Add Dockerfile and dependencies required for container build [RHELDST-1303]

[crungehottman]

This commit introduces the Dockerfile required to build the container
to be deployed to PSI.

This commit also includes additional dependencies required to package
and deploy exodus-gw on OpenShift PSI.

[rohanpm]

Just checking, does microdnf still use /var/yum/cache ? They didn't relocate the cache or change how it works?

The reason I ask is that "rm -rf foo/bar/baz" doesn't fail if the given path never existed in the first place - so this command succeeding doesn't necessarily mean it makes sense.

[crungehottman]

It appears that microdnf has not changed the location of the cache nor its caching behavior, but yum cache is stored in /var/cache/yum, not /var/yum/cache.

Fixed:
before (microdnf clean all removed some cache but ignored rm -rf /var/yum/cache, as the dir does not exist):

[crungeho@localhost exodus-gw]$ podman ps
CONTAINER ID  IMAGE                                  COMMAND  CREATED         STATUS             PORTS                   NAMES
b8fcfd563763  quay.io/exodus/exodus-gw:RHELDST-1303           10 seconds ago  Up 10 seconds ago  0.0.0.0:8080->8080/tcp  laughing_wozniak
[crungeho@localhost exodus-gw]$ podman exec -it b8fcfd563763 ls /var/cache/yum
lock

after (entire /var/cache/yum directory removed):

[crungeho@localhost exodus-gw]$ podman ps
CONTAINER ID  IMAGE                            COMMAND  CREATED        STATUS            PORTS                   NAMES
85ab311eeb21  localhost/exodus-gw/test:latest           4 seconds ago  Up 4 seconds ago  0.0.0.0:8080->8080/tcp  lucid_zhukovsky
[crungeho@localhost exodus-gw]$ podman exec -it 85ab311eeb21 ls /var/cache/yum
ls: cannot access '/var/cache/yum': No such file or directory
Error: exec session exited with non-zero exit code 2: OCI runtime error
[crungeho@localhost exodus-gw]$ podman exec -it 85ab311eeb21 ls /var/cache
ldconfig

[rohanpm]

I'd suggest rebasing this as well, as there are conflicts in requirements.in & requirements.txt.

I'd expect the conflicts in requirements.txt to require running pip-compile again, i.e. git probably will not be able to automatically resolve them.