API: Parse channel's tags

[ChunkyProgrammer]

NOTE: Took the non-broken parts from this PR: https://github.com/iv-org/invidious/pull/4026 for channel tags

In FreeTube, we display the channel's tags in an about tab and I'd like to add support for displaying tags when using the Invidious API (https://github.com/FreeTubeApp/FreeTube/issues/1359)

Tags: auto generated channel (Minecraft - Topic): /api/v1/channels/UCQvWX73GQygcwXOTSf_VDVg

{
...
"tags":["Video game","Indie game","Xbox One","New Nintendo 3DS","PS3","Nintendo Switch","Wii U","Fire OS","Mac operating systems","Apple TV","Xbox 360","PlayStation Vita","PS4","Windows","Linux","Nintendo 3DS","iOS","Windows Phone","iPadOS","Java","Android","tvOS","ChromeOS"]
...
}

other channel (Mr Beast): /api/v1/channels/UCX6OQ3DkcsbYNE6H8uQQuVA

{
...
"tags":["mrbeast6000","beast","mrbeast","Mr.Beast","mr"]
...
}