Improve sync deletion warnings

[keikari]

-Show warning about synced channels on account deletion, if user has any synced channels
-On channel deletion, don't show the warning about synced channels, if user doesn't have any synced channels
-selectHasYoutubeChannels used to always return true due to it working previously like this: Number.isInteger(youtubeChannels?.length) (returned true for an array with length of 0)

Channel deletion warning images:

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Note:

Changing the selectHasYoutubeChannels to return false, when account doesn't have any connected YouTube channels, changes how the empty channel page looks.

Images:

OLD:

NEW:

[tzarebczan]

Awesome, thank you!