* don't use old hardcoded rule for validating imported posts
* fix http verb in doc
* Use client config
* Handle local mode
* E2E tests
* Enforce default if unable to use real limit
* Unit tests
* Fix tests
* Use model.PostMessageMaxRunesV2 as lower default
* Update direct post message length validation
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Co-authored-by: Mattermost Build <build@mattermost.com>
Co-authored-by: streamer45 <cstcld91@gmail.com>