fix: truncating caldav subscription data before saving on DB

[madbob]

• Resolves: Truncate calendar subscriptions display name to 100 chars before saving it #54859

Summary

In $subscriptionPropertyMap I've added, for "string" properties, the maximum length, to know how to properly truncate incoming values.

Note: I've found that in $subscriptionPropertyMap array both stripalarms and stripattachments were marked as "string", since the introduction of those datatypes. But in database schema those are always been "smallint" (boolean) values.

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)
• Labels added where applicable (ex: bug/enhancement, 3. to review, feature component)
• Milestone added for target branch/version (ex: 32.x for stable32)