Update TypeScript to 3.8

[xirzec]

This PR catches us up to TS 3.8 since 3.9 is due out soon. I will merge this after we release for May.

[xirzec]

CI failure look like a bad tsconfig in cosmos:

samples/tsconfig.json(3,5): error TS5053: Option 'noEmit' cannot be specified with option 'composite'

[southpolesteve]

@xirzec Feel free to remove composite from samples tsconfig.json if that fixes it. Honestly sort of regret splitting up our package into TS projects. Its been a headache. Invoking the TS compiler 3 different times was not terribly slow.

[jeremymeng]

Looks good. Add Storage label for service attention.

[xirzec]

Now cosmos legs are complaining about msiexec not being a valid command. @southpolesteve any clue as to what needs to happen here?

[southpolesteve]

Can you retry the tests? That's the emulator failing to start. No idea why it would fail with that error. Possible it got run on some agent that didn't have that exe. Strange, but not without precedent to get a weird agent.

[HarshaNalluru]

/cc - @danieljurek for the emulator issue.

[HarshaNalluru]

Update -
@danieljurek opened a PR #8689 for to fix the issue.

[Issue is caused by running the PowerShell commands to get the emulator to execute the samples in a Linux VM as a separate "Job", #8689 removes that separate-samples-job since the samples are already being executed as part of the Tests-Job]