[Feature]: Restore Realtime Inventory Lookup Functionality

[alanbixby]

In #3208, I added item numbers to all of the entries in the Newegg US store - however I'm realizing this is currently accomplishing nothing since the realtimeInventoryLookup has no coverage (never is called).

Realtime lookups (API based instead of web scraper) were disabled in v3.2.0 e67d97f#diff-df5398bf4301cdf9301ed7143928adb248c73ce1bfefc70be38084c51580ec93R364

Do we know - was this removed simply due to the lack of a try-catch (#676), or were there other issues at play like conflicts with the proxy/captcha deterrents?