Special case parse in base 10

[ndren]

This PR special cases base 10 integer parsing to speed it up using the Rust stdlib.

Some code I used to test (run locally, I don't have a wasm build)

N ← 1e6
⊃($LongNumsFill ⊙◌⍜now⋕₁₀ ⬚@0 °⋕ ⇡ N
| $LongNumsBoxed ⊙◌⍜now⋕₁₀ °⋕ ⇡ N
| $ShortNumsFill ⊙◌⍜now⋕₁₀ ⬚@0 °⋕ ▽ (÷10 N) ⇡ 10
| $ShortNumsBox ⊙◌⍜now⋕₁₀ °⋕ ▽ (÷10 N) ⇡ 10
)

Metric	main	PR	Speedup (%)
LongNumsFill	0.494306	0.355260	28.13%
LongNumsBoxed	0.626325	0.479558	23.43%
ShortNumsFill	0.351373	0.316105	10.04%
ShortNumsBox	0.493949	0.447104	9.48%

Note this code parses f64 more accurately than the code that was previously in use, so for some edge cases it would behave differently by a few ULP. Is that acceptable? (What's nice about this is that it now matches the results of using a float literal, since it now rounds correctly)

Example:

⋕₁₀ "3.14159265358979285"
# Before: π
# After: ~π

[kaikalii]

Specifying π and co to the maximum precision should parse to π.