fix(typescript-estree): handle running out of fs watchers

[bradzacher]

Fixes #1080

I followed typescript's lead here, and fall back to polling if chokidar throws an error when attempting to use fs watchers.

I also added support for reusing watchers, to attempt to conserve resources, and reduce the total number of watchers that we setup.

I also decided it was time to setup some logging to help with debugging.
The logging can be shown via DEBUG=typescript-eslint:* yarn lint

[codecov]

Codecov Report

Merging #1088 into master will decrease coverage by 0.05%.
The diff coverage is 76.92%.

@@            Coverage Diff            @@
##           master   #1088      +/-   ##
=========================================
- Coverage   94.06%     94%   -0.06%     
=========================================
  Files         115     115              
  Lines        5086    5107      +21     
  Branches     1423    1426       +3     
=========================================
+ Hits         4784    4801      +17     
- Misses        174     177       +3     
- Partials      128     129       +1

Impacted Files	Coverage Δ
packages/typescript-estree/src/parser.ts	92.2% <100%> (+0.31%)	⬆️
packages/typescript-estree/src/tsconfig-parser.ts	85.24% <68.96%> (-1.67%)	⬇️