Patch quickstart workflow for devcontainer

[clmccart]

What this PR does / why we need it:
This PR patches a few small issues with the devcontainer quickstart workflow.

• Injects environmeent variables from .env file into .devcontainer/Dockerfile and ./Dockerfile so that user does not have to pass secrets in multiple locations.
• Installs sudo in the devcontainer (needed for downstream mv commands)
• runs "make generate" before build command in the Dockerfile

Special notes for your reviewer:
To Test:

• spin up a new devcontainer by cloning the repo, adding the .env file following README quickstart guidelines. Devcontainer and solution should build with no errors.

If applicable:

this PR contains documentation
this PR contains tests

[frodopwns]

@Azadehkhojandi could you have someone on your side who is familiar with the devcontainer workflow take a look at this PR?

[jananivMS]

Looks good to me and I've tested it and it works too. But will wait for Stephen, Az, Priya to also take a look before approving.

[JasonTheDeveloper]

There's a potential issue if new users try to build the Dockerfile if zz_generated.deepcopy.go isn't generated prior. You've added RUN make generate to the Dockerfile but because hack has been added to .dockerignore, zz_generated.deepcopy.go isn't generated inside the container and if make generate isn't executed prior to building the image, zz_generated.deepcopy.go wont be copied into the image, and as a result the image will fail to build.

I would suggest running make generate when running make set-kindcluster and removing RUN make generate from the Dockerfile, or remove hack from .dockerignore to allow boilerplate.go.txt to be copied into the image.

[JasonTheDeveloper]

Looks good to me!