Rewrite hasLocalStorage check to not produce localStorage-entries

[Andr3wid]

Description

Existence of the localStorage API was probed so far by creating (and immediately deleting) a localStorage-entry. This is undesirable behaviour in case a page wishes to not have the localStorage-API utilized in any way.

This PR introduces the following changes:

• Determine existence of the localStorage-API by checking if getItem and setItem functions are available instead of setting a storage item
• Handle exceptions directly in the getItem/setItem wrapper functions (e.g. if access is denied or quota got exceeded)

Anyways, a localStorage item would still be set if certain feature of the player-UI are used. PR is a followup to introduce disabling of localStorage.

Checklist (for PR submitter and reviewers)

• CHANGELOG entry

[felix-hoc]

nice, just some suggestions :)

[felix-hoc]

the isLocalStorageAvailable() check does not require try-catch, that's already done internally. So we could pull it out of the try block and do an early return, or wrap the whole try-catch block with it. (same for getItem())

[Andr3wid]

Ah yes, you are right. I thought that, when browser prohibits access, exceptions are triggered when actually trying to call getItem / setItem, but it already happens when trying to access window.localStorage. Hence, it's already covered in isLocalStorageAvailable.

I removed the try-catches in this commit: Removed superfluous try-catch

Let's have a call if you meant it in a different way :)

[felix-hoc]

IMO warn is too high of a log level, as we will always check for certain localStorage keys. I'd suggest debug or removing the log completely.

[Andr3wid]

Removed the log entirely as well in Removed superfluous try-catch. Just not a fan of empty catch blocks :)