Optimize valid integer values decode

[ypconstante]

Today decode always converts numbers to strings and then back to number to make sure they are not out of range. We can check if they are in range to avoid this conversion, reducing memory usage.

##### With input google_message1_proto2 #####
Name                                                      ips        average  deviation         median         99th %
decode (optimize-decode-integer-0191397-decode)      445.61 K        2.24 μs  ±1292.99%        2.13 μs        3.18 μs
decode (main-4c7b3e8-decode)                         440.47 K        2.27 μs  ±1112.84%        2.16 μs        3.05 μs

Comparison: 
decode (optimize-decode-integer-0191397-decode)      445.61 K
decode (main-4c7b3e8-decode)                         440.47 K - 1.01x slower +0.0262 μs

Memory usage statistics:

Name                                               Memory usage
decode (optimize-decode-integer-0191397-decode)         2.91 KB
decode (main-4c7b3e8-decode)                            3.85 KB - 1.32x memory usage +0.94 KB

**All measurements for memory usage were the same**

##### With input google_message1_proto3 #####
Name                                                      ips        average  deviation         median         99th %
decode (main-4c7b3e8-decode)                         444.80 K        2.25 μs  ±1177.60%        2.13 μs        3.16 μs
decode (optimize-decode-integer-0191397-decode)      439.76 K        2.27 μs  ±1565.74%        2.13 μs        3.34 μs

Comparison: 
decode (main-4c7b3e8-decode)                         444.80 K
decode (optimize-decode-integer-0191397-decode)      439.76 K - 1.01x slower +0.0258 μs

Memory usage statistics:

Name                                               Memory usage
decode (main-4c7b3e8-decode)                            4.07 KB
decode (optimize-decode-integer-0191397-decode)         3.39 KB - 0.83x memory usage -0.67969 KB

**All measurements for memory usage were the same**

##### With input google_message2 #####
Name                                                      ips        average  deviation         median         99th %
decode (optimize-decode-integer-0191397-decode)       10.70 K       93.46 μs     ±5.33%       92.92 μs      100.43 μs
decode (main-4c7b3e8-decode)                          10.68 K       93.64 μs     ±6.57%       93.17 μs      100.37 μs

Comparison: 
decode (optimize-decode-integer-0191397-decode)       10.70 K
decode (main-4c7b3e8-decode)                          10.68 K - 1.00x slower +0.181 μs

Memory usage statistics:

Name                                                    average  deviation         median         99th %
decode (optimize-decode-integer-0191397-decode)        96.09 KB     ±0.01%       96.09 KB       96.09 KB
decode (main-4c7b3e8-decode)                           96.41 KB     ±0.01%       96.41 KB       96.41 KB

Comparison: 
decode (optimize-decode-integer-0191397-decode)        96.09 KB
decode (main-4c7b3e8-decode)                           96.41 KB - 1.00x memory usage +0.31 KB

[whatyouhide]

Can we leave a comment in the code documenting why we're doing this?

[ypconstante]

Added comments to roundtrip functions

[whatyouhide]

Thank you! 🫶