Build and deploy ARM-based containers

[GaryGSC]

Now that ECS Fargate supports ARM containers, we can supposedly see 40 percent better price-performance at 20 percent lower cost. I believe all of the languages we're likely to use can compile to ARM, so Fargate support for ARM was our last remaining roadblock.

Taking a cursory look at the required steps, it'd involve:

• Adding a docker/setup-qemu-action step so that the build environment can emulate ARM
• Telling the docker/build-push-action step to build for ARM
• Telling Fargate that we're deploying using ARM (It looks like a 1 line change to the task definition, but I imagine that'd require plumbing some configuration through one or more TF modules)

I'd like to think the overall impact to our build/deployment times should be small.

[GaryGSC]

Dockerfiles for ARM-based containers may require a little modification for those using architecture-specific binaries, like for OracleDB.

[GaryGSC]

Linux ARM-based binaries are available for Oracle Instant Client nowadays. I don't think that should be a blocker any more.