test(typescript-estree): correct storing regexp in snapshots

[armano2]

• drop usage of JSON parse/stringify in tests

This change fixes issue with comparing regexp fields in snapshots and alignment tests.

This code has been extracted from #1389

[bradzacher]

LGTM - thanks for this

[codecov]

Codecov Report

Merging #1393 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1393   +/-   ##
=======================================
  Coverage   94.11%   94.11%           
=======================================
  Files         140      140           
  Lines        6028     6028           
  Branches     1709     1709           
=======================================
  Hits         5673     5673           
  Misses        191      191           
  Partials      164      164

Impacted Files	Coverage Δ
packages/typescript-estree/src/parser.ts	94.06% <ø> (ø)	⬆️
...kages/eslint-plugin/src/rules/no-dynamic-delete.ts	100% <0%> (ø)	⬆️
...nt-plugin/src/rules/space-before-function-paren.ts	100% <0%> (ø)	⬆️
...nt-plugin/src/rules/no-untyped-public-signature.ts	100% <0%> (ø)	⬆️