Update bash scripting, remove jq requirement, add nvme mounting

[jlester-msft]

fixes #616
fixes #454

This code change makes 3 main changes to TesApi.Web/BatchScheduler.cs:

1. Changes the definition of the bash script to use more C# @strings. Which makes it much easier to read and work with. Note that set -e makes it so any command which fails during bash script execution will trigger an exit. This means some commands like the grep in nvme_devices=$(nvme list -o json | grep -oP ""\""DevicePath\"" : \""\K[^\""]+"" || true) needs a || true so that if no match is found the script doesn't end. However, most of the other commands don't require && chaining anymore.
2. Removes the jq install requirement for ubuntu and uses a "here doc" style python3 replacement (see Azure Batch start-up script optimization #616)
3. Looks for nvme devices and mounts them as a single RAID0 array onto ${AZ_BATCH_NODE_ROOT_DIR}/tasks/workitems (/mnt/batch/tasks/workitems). Software RAID seems performant and lvm and mdadm RAID0 devices seem to have similar performance. mdadm is used as it is the easier/more mature solution.

These changes have been tested on a few large example workflows. And on some L-series test workloads. Could require additional hardening but seems to be working well enough at the moment.

@BMurri + @MattMcL4475

[BMurri]

I recall this being discussed. I don't recall if an issue was opened. I'll go over this (and merge with main, since I'm the last to touch the start-task and I'm certain that's where the merge conflicts mainly are) on Monday.

@jlester-msft could you please respond here with the issue number? Thank you!

[jlester-msft]

The L-series NVME issue is #454. That issue was asking for tes-runner to do this; however, we can have bash do this for now. I don't think we need to spend the dev time to code this into tes-runner right now.

[BMurri]

@jlester-msft This has been merged with main and will definitely be more maintainable. It does substantially alter the 1st main change mentioned in the description, though.