urldecode group principals in Cal- and CardDAV backend

[georgehrke]

fixes#4885

before:

array(4) {
["admin"]=>
string(23) "principals/groups/admin"
["x y"]=>
string(21) "principals/groups/x+y"
["x&y"]=>
string(23) "principals/groups/x%26y"
["x/y"]=>
string(23) "principals/groups/x%2Fy"
}

after:

array(4) {
["admin"]=>
string(23) "principals/groups/admin"
["x y"]=>
string(21) "principals/groups/x y"
["x&y"]=>
string(21) "principals/groups/x&y"
["x/y"]=>
string(21) "principals/groups/x/y"
}

There are absolutely no group-share related tests neither the Cal- nor the CardDav backend tests ...
We should maybe add them sometime soonish

[georgehrke]

Why the heck are the tests failing? 😕

https://github.com/nextcloud/server/blob/master/apps/dav/tests/unit/CardDAV/CardDavBackendTest.php#L92L94
https://github.com/nextcloud/server/blob/master/apps/dav/tests/unit/CalDAV/AbstractCalDavBackendTest.php#L74L76

[codecov]

Codecov Report

Merging #5298 into master will decrease coverage by 22.87%.
The diff coverage is 0%.

@@ Coverage Diff @@## master #5298 +/- ##
=============================================
- Coverage 54.15% 31.28% -22.88% + Complexity 22317 22316 -1 
=============================================
Files 1380 1380 Lines 85432 84822 -610 Branches 1321 1321 =============================================
- Hits 46264 26533 -19731 - Misses 39168 58289 +19121

Impacted Files	Coverage Δ	Complexity Δ
apps/dav/lib/CardDAV/CardDavBackend.php	0% <0%> (-85.69%)	88 <0> (ø)
apps/dav/lib/CalDAV/CalDavBackend.php	0% <0%> (-86.01%)	218 <0> (ø)
apps/files_sharing/lib/AppInfo/Application.php	0% <0%> (-100%)	3% <0%> (-1%)
lib/private/Files/Mount/CacheMountProvider.php	0% <0%> (-100%)	4% <0%> (ø)
lib/private/TagManager.php	0% <0%> (-100%)	4% <0%> (ø)
lib/public/Comments/CommentsEvent.php	0% <0%> (-100%)	3% <0%> (ø)
lib/private/DB/OCSqlitePlatform.php	0% <0%> (-100%)	5% <0%> (ø)
lib/private/Files/Mount/LocalHomeMountProvider.php	0% <0%> (-100%)	1% <0%> (ø)
apps/user_ldap/lib/Mapping/UserMapping.php	0% <0%> (-100%)	1% <0%> (ø)
apps/user_ldap/lib/Migration/UUIDFixUser.php	0% <0%> (-100%)	1% <0%> (ø)
... and 368 more

[georgehrke]

Fixed the tests

[nickvergessen]

Technically speaking there was an evil mistake in there, when you have two groups with the same name apart from space vs. plus. If you shared something with space, plus had access.