Migrate NSS ARM docker-worker images to monopacker-built images in a Worker Manager managed worker pool

[petemoore]

Currently NSS arm64 workers (a1.xlarge ec2 instance type) are manually provisioned under localprovisioner provisioner ID, and were manually created by Miles. We should integrate them into monopacker, which involves:

1. Adding support for arm64 machine images in monopacker
2. Building new arm64 docker-worker worker images, that include fixes from bug 1665052
3. Creating a firefox-ci worker pool that replaces the single worker nss-static-aarch64 in ci-configuration repo and uses the new images created in 2)
4. Purging the previous worker objects from firefox-ci taskcluster instance and firefox-ci AWS account, to ensure none of the old world lingers

Notes from Miles:

docker arm64: https://www.docker.com/blog/getting-started-with-docker-for-arm-on-linux/

Docker:
- curl -fsSL test.docker.com -o get-docker.sh && sh get-docker.sh

Nvm:
- curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.35.3/install.sh | bash
- export NVM_DIR="$([ -z "${XDG_CONFIG_HOME-}" ] && printf %s "${HOME}/.nvm" || printf %s "${XDG_CONFIG_HOME}/nvm")"
- [ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh" # This loads nvm

Node:
- nvm install 12.18.0 # or whatever current tc uses

Yarn:
- curl -sS https://dl.yarnpkg.com/debian/pubkey.gpg | sudo apt-key add -
- echo "deb https://dl.yarnpkg.com/debian/ stable main" | sudo tee /etc/apt/sources.list.d/yarn.list
- sudo apt update && sudo apt install yarn

Gvm:
- bash < <(curl -s -S -L https://raw.githubusercontent.com/moovweb/gvm/master/binscripts/gvm-installer)
- source /home/ubuntu/.gvm/scripts/gvm
- sudo apt-get install bison

Go:
- sudo apt  install golang-go
- gvm install go1.13 # or whatever current tc uses
- gvm use go1.13

Worker-runner:
- # start-worker arm64 (built manually, releases not built automatically)
- git clone https://github.com/taskcluster/taskcluster.git
- cd taskcluster/tools/worker-runner
- go build -o /usr/local/bin/start-worker ./cmd/start-worker

Worker-runner start script:
#!/bin/bash
set -exv
/etc/taskcluster/worker-runner/start-worker.yml 2>&1 | logger --tag docker-worker

Docker-worker
- curl -L -o docker-worker.tgz https://github.com/taskcluster/taskcluster/releases/download/v30.1.1/docker-worker-x64.tgz
- tar xvf docker-worker.tgz
- cd /home/ubuntu/docker-worker
- npm rebuild

We probably want to split this up into smaller issues, as there are several non-trivial pieces of work here.