Factor out collector methods on models into traits (#3055) #5849

Job	Run time
Build docs	40s
Examples	2m 39s
Check minimal versions	26s
Test (macOS)	2m 4s
Test (nightly)	1m 42s
Test (stable)	2m 34s
Test (beta)	3m 0s
Test (Windows)	5m 12s
Test (native-tls)	2m 22s
Test (no default features)	50s
Test (no cache)	2m 29s
Test (no gateway)	1m 45s
Test (unstable Discord API features)	2m 47s
Test (zlib compression)	2m 31s
Test (zstd compression)	2m 25s
Test (zlib and zstd compression)	2m 27s
Test (chrono, chrono)	55s
Test (unstable API + typesize, default unstable typesize, true)	1m 4s
Test (builder without model, builder, true)	42s
Test (unstable Discord API (no default features), unstable, true)	31s
MSRV	0s
	39m 5s

Provide feedback