fix(scope-manager): support type predicates

[bradzacher]

Fixes #2462

[typescript-eslint]

Thanks for the PR, @bradzacher!

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[codecov]

Codecov Report

Merging #2493 into master will decrease coverage by 0.00%.
The diff coverage is 66.66%.

@@            Coverage Diff             @@
##           master    #2493      +/-   ##
==========================================
- Coverage   92.84%   92.84%   -0.01%     
==========================================
  Files         290      290              
  Lines        9354     9360       +6     
  Branches     2622     2623       +1     
==========================================
+ Hits         8685     8690       +5     
  Misses        321      321              
- Partials      348      349       +1     

Flag	Coverage Δ
#unittest	92.84% <66.66%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...ckages/scope-manager/src/referencer/TypeVisitor.ts	89.33% <66.66%> (-0.95%)	⬇️
...ackages/scope-manager/src/referencer/Referencer.ts	93.93% <0.00%> (+0.07%)	⬆️