Improve Toggle code by use Arc for avoid clone rules.

[huacnlee]

Benchmark result:

format_050              time:   [6.4239 µs 6.4465 µs 6.4696 µs]
format_100              time:   [11.020 µs 11.056 µs 11.109 µs]
format_400              time:   [30.762 µs 31.317 µs 32.096 µs]
format_html             time:   [441.20 µs 481.38 µs 524.98 µs]
halfwidth_english       time:   [2.0451 µs 2.0468 µs 2.0489 µs]
format_json             time:   [55.354 µs 55.384 µs 55.418 µs]
format_json_2k          time:   [8.2878 ms 8.3047 ms 8.3228 ms]
format_jupyter          time:   [204.91 µs 205.54 µs 206.18 µs]
format_markdown         time:   [1.3007 ms 1.3041 ms 1.3078 ms]

spellcheck_50           time:   [1.3133 µs 1.3159 µs 1.3185 µs]
spellcheck_100          time:   [2.4848 µs 2.4908 µs 2.4971 µs]
spellcheck_400          time:   [7.9101 µs 7.9280 µs 7.9486 µs]

lint_markdown           time:   [1.3364 ms 1.3388 ms 1.3418 ms]
lint_json               time:   [60.410 µs 60.557 µs 60.723 µs]
lint_html               time:   [367.54 µs 367.99 µs 368.57 µs]
lint_javascript         time:   [186.25 µs 186.46 µs 186.64 µs]
lint_yaml               time:   [423.19 µs 423.95 µs 424.63 µs]
lint_to_json            time:   [1.3450 ms 1.3487 ms 1.3523 ms]
lint_to_diff            time:   [1.4101 ms 1.4136 ms 1.4174 ms]