Intern tree strings

[sharwell]

Improves the performance of the call stacks by interning the strings used in comparison operations.

:memo: Please make sure to not rebase or squash this change during the merge process.

[codecov-io]

Codecov Report

Merging #430 into master will increase coverage by 0.14%. The diff coverage is 58.82%.

@@            Coverage Diff             @@
##           master     #430      +/-   ##
==========================================
+ Coverage   17.44%   17.58%   +0.14%     
==========================================
  Files         213      214       +1     
  Lines      123790   123828      +38     
  Branches    11971    11973       +2     
==========================================
+ Hits        21590    21773     +183     
- Misses     101189   101194       +5     
+ Partials     1011      861     -150

Flag	Coverage Δ
#2017	17.58% <58.82%> (+0.14%)	:arrow_up:
#Debug	17.58% <58.82%> (+0.14%)	:arrow_up:
#Release	100% <ø> (ø)	:arrow_up:

Impacted Files	Coverage Δ
src/TraceEvent/Stacks/CallTree.cs	49.81% <42.1%> (-0.1%)	:arrow_down:
src/TraceEvent/Stacks/Interner.cs	68.75% <68.75%> (ø)
src/PerfView/StackViewer/PerfDataGrid.xaml.cs	34.02% <0%> (ø)	:arrow_up:
...c/TraceEvent/Parsers/ClrPrivateTraceEventParser.cs	19.58% <0%> (+0.03%)	:arrow_up:
src/TraceEvent/TraceEvent.cs	63.34% <0%> (+0.1%)	:arrow_up:
src/TraceEvent/DynamicTraceEventParser.cs	67.49% <0%> (+0.15%)	:arrow_up:
src/TraceEvent/TraceLog.cs	61.25% <0%> (+0.2%)	:arrow_up:
src/TraceEvent/Parsers/TplTraceEventParser.cs	49.65% <0%> (+0.22%)	:arrow_up:
... and 7 more

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[sharwell]

Updated after repository rewrite