fix: Do not escape wildcard in objectclass from admin config

[jcdelepine]

The default objectclass filter in Horde's LDAP config is ['*'], but this value was being escaped to '\2A', resulting in invalid filters like (objectclass=\2A) instead of (objectclass=*). This patch disables escaping for values coming from trusted configuration.

Values from user input are still escaped to prevent LDAP injection.

[ralflang]

Thank you very much.

[ralflang]

There are some rebase conflicts and the CI is red. I will fixup this.

[ralflang]

Released as https://packagist.org/packages/horde/ldap#v3.0.0alpha9 - thank you very much.

Notes:

• If you give upstream write access to your PR branch, we can simplify touchups before release
• I edited the commit message to contain the prefix "fix: " in the first line. The commit should still display you as the author.
• Merged to a separate branch, cherry-picked/rebased the actual commit on FRAMEWORK_6_0 so it would apply without warnings
• Repaired the test suite. Upside: It's now working correctly and pointing out actual problems. Downside: It's showing problems with the diff test and I have not yet looked into it if this means the Horde_Ldap_Diff class is broken or something is wrong with the fixtures.