Compile version-specific functions

[nickrobinson251]

Speed up first call by splitting the top-level parse_network into version-specific function sooner.

(xref #52)

Some quick benchmarks below

---

v33 file on this branch:

julia> @time parse_network("../PowerSystemsTestData/ACTIVSg70k/ACTIVSg70k.RAW");
  0.957465 seconds (640.32 k allocations: 135.810 MiB, 3.77% gc time, 70.28% compilation time)

julia> @time parse_network("../PowerSystemsTestData/ACTIVSg70k/ACTIVSg70k.RAW");
  0.284085 seconds (1.16 k allocations: 96.066 MiB, 8.94% gc time)

on main:

julia> @time parse_network("../PowerSystemsTestData/ACTIVSg70k/ACTIVSg70k.RAW");
  1.548256 seconds (1.14 M allocations: 164.239 MiB, 3.83% gc time, 80.19% compilation time)

julia> @time parse_network("../PowerSystemsTestData/ACTIVSg70k/ACTIVSg70k.RAW");
  0.267670 seconds (1.19 k allocations: 96.073 MiB)

---

v30 file on this branch:

julia> @time parse_network("raw/realistic30.raw");
  0.863707 seconds (592.45 k allocations: 103.168 MiB, 3.84% gc time, 73.19% compilation time)

julia> @time parse_network("raw/realistic30.raw");
  0.176325 seconds (1.24 k allocations: 66.259 MiB, 8.40% gc time)

on main:

julia> @time parse_network("raw/realistic30.raw");
  1.336480 seconds (1.06 M allocations: 129.593 MiB, 1.94% gc time, 85.16% compilation time)

julia> @time parse_network("raw/realistic30.raw");
  0.200634 seconds (1.27 k allocations: 66.265 MiB, 9.33% gc time)

---

this branch:

julia> @time parse_network("raw/realistic29.raw");
  0.880513 seconds (591.73 k allocations: 111.991 MiB, 3.25% gc time, 75.70% compilation time)

julia> @time parse_network("raw/realistic29.raw");
  0.217870 seconds (1.24 k allocations: 75.134 MiB, 5.17% gc time)

on main:

julia> @time parse_network("raw/realistic29.raw");
  1.325899 seconds (1.06 M allocations: 138.400 MiB, 1.88% gc time, 83.74% compilation time)

julia> @time parse_network("raw/realistic29.raw");
  0.211890 seconds (1.27 k allocations: 75.141 MiB, 8.33% gc time)

[codecov-commenter]

Codecov Report

Merging #57 (02c660d) into main (3ecca18) will decrease coverage by 0.04%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main      #57      +/-   ##
==========================================
- Coverage   94.56%   94.51%   -0.05%     
==========================================
  Files           3        3              
  Lines         331      328       -3     
==========================================
- Hits          313      310       -3     
  Misses         18       18              

Impacted Files	Coverage Δ
src/parsing.jl	98.59% <100.00%> (-0.02%)	⬇️

---

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[nickrobinson251]

Numbers from before #47(of course, no numbers for the v33 file) :

julia> @time parse_network("raw/realistic30.raw");
 0.566602 seconds (331.92 k allocations: 82.066 MiB, 13.27% gc time, 56.64% compilation time)

julia> @time parse_network("raw/realistic30.raw");
 0.192522 seconds (1.13 k allocations: 60.640 MiB, 2.68% gc time)

julia> @time parse_network("raw/realistic29.raw");
 0.518445 seconds (331.92 k allocations: 90.753 MiB, 2.80% gc time, 64.44% compilation time)

julia> @time parse_network("raw/realistic29.raw");
 0.190273 seconds (1.13 k allocations: 69.327 MiB, 3.11% gc time)

So this PR gets us a lot closer to those numbers, but not all the way back.