[Engineering] Lower time for botbuilder-azure tests

[denscollo]

Addresses #2338

Description

Updates the warnings raised in some tests of the BotBuilder-Azure library to be shown once for the describe instead of each test inside it.

Specific Changes

Update the tests in the files blobStorage.test.js and cosmosDbStorage.test.js to run the emulator check once in the describes to raise a warning instead of running it in each test of the describe. This change reduces the time for the tests a little bit and makes the test report more readable.

We also updated some eslint warnings in these files.

Testing

Here you can compare the times for each test running when moving the warning to be shown once for the describe and how it is more readable in the report.

Note: the times vary in each run, but in general there is a slight reduction in the times.

[EricDahlvang]

lgtm