Use the new SQL parser as default

[mikker]

This PR switches the default SQL parser to the new one.

The old one is still provided so users can easily switch if they encounter any problems.

In a few months we'll remove the old approach completely.

[codecov-io]

Codecov Report

Merging #730 into master will decrease coverage by 2.52%.
The diff coverage is 71.42%.

@@            Coverage Diff             @@
##           master     #730      +/-   ##
==========================================
- Coverage   64.35%   61.83%   -2.53%     
==========================================
  Files         103      105       +2     
  Lines        3100     3322     +222     
==========================================
+ Hits         1995     2054      +59     
- Misses       1105     1268     +163

Impacted Files	Coverage Δ
lib/elastic_apm/sql.rb	77.77% <100%> (ø)	⬆️
lib/elastic_apm/config.rb	78.82% <50%> (-0.82%)	⬇️
lib/elastic_apm/sql_summarizer.rb
lib/elastic_apm/sql/signature.rb	20.54% <0%> (ø)
lib/elastic_apm/sql/tokenizer.rb	18.18% <0%> (ø)
lib/elastic_apm/sql/tokens.rb	100% <0%> (ø)

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[estolfo]

🎉