Create a new API to retrieve interpreter details with the ability to cache the details

[DonJayamanne]

Fixes #1569
Partial work for #1351
This PR introduced about to get interpreter info and cache it. The information built will be used to build the display name and used in analysis engine (separate PR).
So, this PR focuses on being backwards compatible.

This pull request:

• Has a title summarizes what is changing
• Includes a news entry file (remember to thank yourself!)
• Has unit tests & code coverage is not adversely affected (within reason)
• Works on all actively maintained versions of Python (e.g. Python 2.7 & the latest Python 3 release)
• Works on Windows 10, macOS, and Linux (e.g. considered file system case-sensitivity)

[codecov]

Codecov Report

❗ No coverage uploaded for pull request base (master@f18a5ee). Click here to learn what that means.
The diff coverage is 77.98%.

@@            Coverage Diff            @@
##             master    #1567   +/-   ##
=========================================
  Coverage          ?   71.42%           
=========================================
  Files             ?      277           
  Lines             ?    12983           
  Branches          ?     2334           
=========================================
  Hits              ?     9273           
  Misses            ?     3574           
  Partials          ?      136

Impacted Files	Coverage Δ
src/client/common/process/types.ts	100% <ø> (ø)
src/client/common/types.ts	100% <ø> (ø)
src/client/common/platform/types.ts	100% <ø> (ø)
src/client/interpreter/locators/index.ts	89.58% <ø> (ø)
src/client/interpreter/virtualEnvs/types.ts	100% <ø> (ø)
src/client/linters/errorHandlers/notInstalled.ts	33.33% <0%> (ø)
src/client/activation/interpreterDataService.ts	12.08% <0%> (ø)
...t/interpreter/locators/services/condaEnvService.ts	86.36% <100%> (ø)
src/client/unittests/common/runner.ts	90.32% <100%> (ø)
src/client/common/process/pythonToolService.ts	71.42% <100%> (ø)
... and 24 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update f18a5ee...8f7014e. Read the comment docs.

[brettcannon]

That's quite the title 😉

[DonJayamanne]

Didn't want anyone to waste time reviewing the PR. However I wanted the WIP PR to ensure test get run and I never delete this branch.

This PR is something I was working on during my free time (was getting too tired with debugger). Related to #1351 (laying the ground work for that and a couple of other parts of the extension).

[DonJayamanne]

@Microsoft/pvsc-team This PR is ready for review.