Apex 4 support

[fenuks]

Hello, Apex 4 is recognized as k2.

$ flydigictl info
            Device : 84 (k2)
Battery percentage : 0%
   Connection type : wired
               CPU : wch (ch573)

Battery reporting is also incorrect.

flydigictl dump is saved to https://pastebin.com/N8pTPkQA.

flydigictl leds panics.

panic: TODO: implement

goroutine 96 [running]:
github.com/pipe01/flydigictl/pkg/dbus/pb.ConvertLEDConfiguration(0xc0000f0050)
        /home/fenuks/code/flydigictl/src/flydigictl/pkg/dbus/pb/convert.go:94 +0x20d
github.com/pipe01/flydigictl/pkg/dbus/server.(*Server).GetLEDConfiguration(0x0?)
        /home/fenuks/code/flydigictl/src/flydigictl/pkg/dbus/server/server.go:171 +0xa5
reflect.Value.call({0x7ac040?, 0xc000014690?, 0xc000176c78?}, {0x7ceb29, 0x4}, {0xafd260, 0x0, 0x7ac040?})
        /usr/lib/go/src/reflect/value.go:584 +0xca6
reflect.Value.Call({0x7ac040?, 0xc000014690?, 0x0?}, {0xafd260?, 0x0?, 0x40e627?})
        /usr/lib/go/src/reflect/value.go:368 +0xb9
github.com/godbus/dbus/v5.exportedMethod.Call({{0x7ac040?, 0xc000014690?, 0xc0002020f0?}}, {0xafd260, 0x0, 0x0?})
        /home/fenuks/code/flydigictl/src/gopath/pkg/mod/github.com/godbus/dbus/v5@v5.1.0/default_handler.go:128 +0x1aa
github.com/godbus/dbus/v5.(*Conn).handleCall(0xc0001c2000, 0xc0002020f0)
        /home/fenuks/code/flydigictl/src/gopath/pkg/mod/github.com/godbus/dbus/v5@v5.1.0/export.go:193 +0x565
created by github.com/godbus/dbus/v5.(*Conn).inWorker in goroutine 18
        /home/fenuks/code/flydigictl/src/gopath/pkg/mod/github.com/godbus/dbus/v5@v5.1.0/conn.go:435 +0x273