chore(stdlib) Improve performance of parsing nginx and apache logs

[JakubOnderka]

Summary

Use the same approach like in #1811.

vrl_stdlib/functions/parse_apache_log/common
                        time:   [2.2207 µs 2.2275 µs 2.2352 µs]
                        thrpt:  [447.38 Kelem/s 448.93 Kelem/s 450.31 Kelem/s]
                 change:
                        time:   [−10.442% −8.1507% −4.9371%] (p = 0.00 < 0.05)
                        thrpt:  [+5.1935% +8.8740% +11.659%]
                        Change within noise threshold.
vrl_stdlib/functions/parse_apache_log/combined
                        time:   [5.2362 µs 5.2983 µs 5.4218 µs]
                        thrpt:  [184.44 Kelem/s 188.74 Kelem/s 190.98 Kelem/s]
                 change:
                        time:   [−7.9553% −6.2355% −3.4695%] (p = 0.00 < 0.05)
                        thrpt:  [+3.5942% +6.6502% +8.6428%]
                        Change within noise threshold.
vrl_stdlib/functions/parse_apache_log/error
                        time:   [3.5829 µs 3.5878 µs 3.5945 µs]
                        thrpt:  [278.21 Kelem/s 278.72 Kelem/s 279.11 Kelem/s]
                 change:
                        time:   [−8.2142% −7.9738% −7.7611%] (p = 0.00 < 0.05)
                        thrpt:  [+8.4141% +8.6647% +8.9493%]
                        Performance has improved.

Change Type

• Bug fix
• New feature
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

How did you test this PR?

cargo bench
cargo test

Does this PR include user facing changes?

• Yes. Please add a changelog fragment based on
  our guidelines.
• No. A maintainer will apply the "no-changelog" label to this PR.

Checklist

• Our CONTRIBUTING.md is a good starting place.
• If this PR introduces changes to LICENSE-3rdparty.csv, please
  run dd-rust-license-tool write and commit the changes. More details here.