* feat(backend): add isSensitive to Channel
* feat(backend): support isSensitive in channel endpoints
* feat(frontend/channel-editor): support isSensitive in create/edit channel page
* feat(frontend/channel): show sensitive indicator for sensitive channels
* docs(changelog): add チャンネルをセンシティブ指定できるようになりました
* chore: license header for each file
* chore: add isSensitive of channel to Note object
* chore: Add the SPDX information to each file
Add copyright and licensing information as defined in version 3.0 of
the REUSE Specification.
* tweak format
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Co-authored-by: syuilo <Syuilotan@yahoo.co.jp>
