feat: pathfinder gql service

[pyrorhythm]

hi! i've recently done some work reversing spotify app workflows, and i think 've done a pretty good job with api-partner.spotify.com/pathfinder.
you can see code at my proj (https://github.com/pyrorhythm/libspot/tree/main/pathfinder), we could possibly integrate core logic into golibrespot, with some enhancements like fetching actual gql query hashes from web player and such

[pyrorhythm]

also, i've reversed some restapi requests from spclient here too - https://github.com/pyrorhythm/libspot/tree/main/spc; could also use that as more stable option

[devgianlu]

What is it used for?

[pyrorhythm]

it's a gateway to graphQL service, exposing bulk search endpoints (search suggestions, top search and such)

[pyrorhythm]

also it is used to return complete "Home" page structure

const (
	OpSearchTracks      BadgeOperation = "searchTracks"
	OpSearchAlbums      BadgeOperation = "searchAlbums"
	OpSearchArtists     BadgeOperation = "searchArtists"
	OpSearchPlaylists   BadgeOperation = "searchPlaylists"
	OpSearchPodcasts    BadgeOperation = "searchPodcasts"
	OpSearchEpisodes    BadgeOperation = "searchFullEpisodes"
	OpSearchUsers       BadgeOperation = "searchUsers"
	OpSearchGenres      BadgeOperation = "searchGenres"
	OpSearchTop         Operation      = "searchTopResultsList"
	OpSearchSuggestions Operation      = "searchSuggestions"

	OpHome                   Operation = "home"
	OpGetAlbum               Operation = "getAlbum"
	OpWhatsNewFeedNewItems   Operation = "whatsNewFeedNewItems"
	OpRecentSearches         Operation = "recentSearches"
	OpSaveRecentSearches     Operation = "saveRecentSearches"
	OpIsFollowingUsers       Operation = "isFollowingUsers"
	OpFeedBaselineLookup     Operation = "feedBaselineLookup"
	OpFetchExtractedColors   Operation = "fetchExtractedColors"
	OpGetDynamicColorsByUris Operation = "getDynamicColorsByUris"
	OpQueryNpvArtist         Operation = "queryNpvArtist"
)