feat(content-moderation): support `custom_comprehend` #17402

Job	Run time
build (ubuntu-latest, linux_openresty, lua-resty-worker-events, t/plugin/[a-k]*)	40m 57s
build (ubuntu-latest, linux_openresty, lua-resty-worker-events, t/plugin/[l-z]*)	37m 15s
build (ubuntu-latest, linux_openresty, lua-resty-worker-events, t/admin t/cli t/config-center-yam...	27m 54s
build (ubuntu-latest, linux_openresty, lua-resty-worker-events, t/node t/pubsub t/router t/script...	26m 17s
build (ubuntu-latest, linux_openresty, lua-resty-events, t/plugin/[a-k]*)	33m 30s
build (ubuntu-latest, linux_openresty, lua-resty-events, t/plugin/[l-z]*)	36m 41s
build (ubuntu-latest, linux_openresty, lua-resty-events, t/admin t/cli t/config-center-yaml t/con...	33m 19s
build (ubuntu-latest, linux_openresty, lua-resty-events, t/node t/pubsub t/router t/script t/secr...	29m 0s
	4h 24m 53s

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