Currently, the web-terminal-operator only supports `x86_64`. For OpenShift 4.6, we will need to support multiple architectures for all the docker images we build.

Describe the solution you'd like
Multi-arch builds for:

• [ ] web-terminal-tooling
• Figure out either how to bundle ~200MB of sources for each arch or a way to reuse multi-arch builds for the tooling we install.
• [ ] web-terminal-exec (can we reuse multi-arch build from machine-exec?)
• [ ] web-terminal-operator