feat(comments): Support mentioning emails

[nickvergessen]

• Required for feat(email): Recognize guests invited via email spreed#13499

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[nickvergessen]

/backport to stable30

[danxuliu]

Looks good, but please add a test in

server/tests/lib/Comments/CommentTest.php

Lines 141 to 200 in 49dd79e

	public function mentionsProvider(): array {
	return [
	[
	'@alice @bob look look, a cook!',
	[['type' => 'user', 'id' => 'alice'], ['type' => 'user', 'id' => 'bob']],
	],
	[
	'no mentions in this message',
	[]
	],
	[
	'@alice @bob look look, a duplication @alice test @bob!',
	[['type' => 'user', 'id' => 'alice'], ['type' => 'user', 'id' => 'bob']],
	],
	[
	'@alice is the author, notify @bob, nevertheless mention her!',
	[['type' => 'user', 'id' => 'alice'], ['type' => 'user', 'id' => 'bob']],
	/* author: */ 'alice'
	],
	[
	'@foobar and @barfoo you should know, @[email protected] is valid' .
	' and so is @[email protected]@foobar.io I hope that clarifies everything.' .
	' cc @23452-4333-54353-2342 @yolo!' .
	' however the most important thing to know is that www.croissant.com/@oil is not valid' .
	' and won\'t match anything at all',
	[
	['type' => 'user', 'id' => '[email protected]@foobar.io'],
	['type' => 'user', 'id' => '23452-4333-54353-2342'],
	['type' => 'user', 'id' => '[email protected]'],
	['type' => 'user', 'id' => 'foobar'],
	['type' => 'user', 'id' => 'barfoo'],
	['type' => 'user', 'id' => 'yolo'],
	],
	],
	[
	'@@chef is also a valid mention, no matter how strange it looks',
	[['type' => 'user', 'id' => '@chef']],
	],
	[
	'Also @"user with spaces" are now supported',
	[['type' => 'user', 'id' => 'user with spaces']],
	],
	[
	'Also @"guest/0123456789abcdef" are now supported',
	[['type' => 'guest', 'id' => 'guest/0123456789abcdef']],
	],
	[
	'Also @"group/My Group ID 321" are now supported',
	[['type' => 'group', 'id' => 'My Group ID 321']],
	],
	[
	'Welcome federation @"federated_group/My Group ID 321" @"federated_team/Former Cirle" @"federated_user/cloudId@http://example.tld:8080/nextcloud"! Now freshly supported',
	[
	['type' => 'federated_user', 'id' => 'cloudId@http://example.tld:8080/nextcloud'],
	['type' => 'federated_group', 'id' => 'My Group ID 321'],
	['type' => 'federated_team', 'id' => 'Former Cirle'],
	],
	],
	];
	}

[danxuliu]

Thanks!

CI failures should be unrelated.