Refactor website specific scriptdata to its own object

[thijsoo]

In the greater refactor of the script data we need to isolate the fields that are mostly just website settings, This might include + siteIconUrl + linkParams + PluginUrl + DismissedAlerts + currentPromotions + Schema + site_name + wistiaEmbedPermission + webinarIntroBlockEditorUrl + blackFridayBlockEditorUrl