add benchmarks for String methods implemented in K/js with js builtins

[alex28sh]

With the purpose of investigating which String methods in Wasm could be implemented similarly to their counterparts in K/Js.
linked issue https://youtrack.jetbrains.com/issue/KT-83156/K-Wasm-rewise-StringBuilder-usages-in-stdlib
Preliminary local evaluation:

Wasm

wasm: microBenchmarks.StringBenchmark.stringIndexOf
Warm-up #0: 0.154017 ms/op
Warm-up #1: 0.159848 ms/op
Warm-up #2: 0.152405 ms/op
Warm-up #3: 0.152419 ms/op
Warm-up #4: 0.151956 ms/op
Iteration #0: 0.158402 ms/op
Iteration #1: 0.157095 ms/op
Iteration #2: 0.158064 ms/op
Iteration #3: 0.158432 ms/op
Iteration #4: 0.156818 ms/op
  ~ 0.157762 ms/op ±0.42%

wasm: microBenchmarks.StringBenchmark.stringRemoveRange
Warm-up #0: 7.24390 ms/op
Warm-up #1: 7.35677 ms/op
Warm-up #2: 7.20336 ms/op
Warm-up #3: 7.54938 ms/op
Warm-up #4: 7.64899 ms/op
Iteration #0: 7.65213 ms/op
Iteration #1: 7.61498 ms/op
Iteration #2: 7.58112 ms/op
Iteration #3: 7.39488 ms/op
Iteration #4: 7.87974 ms/op
  ~ 7.62457 ms/op ±2.0%

wasm: microBenchmarks.StringBenchmark.stringRepeat
Warm-up #0: 1.26310 ms/op
Warm-up #1: 1.33175 ms/op
Warm-up #2: 1.25300 ms/op
Warm-up #3: 1.30432 ms/op
Warm-up #4: 1.36178 ms/op
Iteration #0: 1.34740 ms/op
Iteration #1: 1.36127 ms/op
Iteration #2: 1.33119 ms/op
Iteration #3: 1.33972 ms/op
Iteration #4: 1.33625 ms/op
  ~ 1.34317 ms/op ±0.76%

wasm: microBenchmarks.StringBenchmark.stringReplace
Warm-up #0: 295.580 ms/op
Warm-up #1: 292.284 ms/op
Warm-up #2: 291.719 ms/op
Warm-up #3: 277.161 ms/op
Warm-up #4: 298.287 ms/op
Iteration #0: 281.397 ms/op
Iteration #1: 278.939 ms/op
Iteration #2: 303.475 ms/op
Iteration #3: 301.655 ms/op
Iteration #4: 808.703 ms/op
  ~ 394.834 ms/op ±51%

Js

js: microBenchmarks.StringBenchmark.stringIndexOf
Warm-up #0: 0.0139317 ms/op
Warm-up #1: 0.0130344 ms/op
Warm-up #2: 0.0137545 ms/op
Warm-up #3: 0.0131107 ms/op
Warm-up #4: 0.0131188 ms/op
Iteration #0: 0.0124660 ms/op
Iteration #1: 0.0126771 ms/op
Iteration #2: 0.0129944 ms/op
Iteration #3: 0.0125529 ms/op
Iteration #4: 0.0126307 ms/op
  ~ 0.0126642 ms/op ±1.4%

js: microBenchmarks.StringBenchmark.stringRemoveRange
Warm-up #0: 13.9127 ms/op
Warm-up #1: 9.10726 ms/op
Warm-up #2: 13.1903 ms/op
Warm-up #3: 11.4397 ms/op
Warm-up #4: 9.67798 ms/op
Iteration #0: 12.5309 ms/op
Iteration #1: 9.72434 ms/op
Iteration #2: 12.9641 ms/op
Iteration #3: 12.8643 ms/op
Iteration #4: 9.72210 ms/op
  ~ 11.5612 ms/op ±13%

js: microBenchmarks.StringBenchmark.stringRepeat
Warm-up #0: 0.206734 ms/op
Warm-up #1: 0.191148 ms/op
Warm-up #2: 0.157657 ms/op
Warm-up #3: 0.164414 ms/op
Warm-up #4: 0.145794 ms/op
Iteration #0: 0.143821 ms/op
Iteration #1: 0.138290 ms/op
Iteration #2: 0.142675 ms/op
Iteration #3: 0.169228 ms/op
Iteration #4: 0.151387 ms/op
  ~ 0.149080 ms/op ±7.2%

js: microBenchmarks.StringBenchmark.stringReplace
Warm-up #0: 19.1304 ms/op
Warm-up #1: 18.8845 ms/op
Warm-up #2: 15.8104 ms/op
Warm-up #3: 21.3412 ms/op
Warm-up #4: 16.5629 ms/op
Iteration #0: 15.5913 ms/op
Iteration #1: 19.4830 ms/op
Iteration #2: 15.6627 ms/op
Iteration #3: 20.8699 ms/op
Iteration #4: 15.5969 ms/op
  ~ 17.4407 ms/op ±13%

indexOf, repeat, replace are working faster in K/Js

[alex28sh]