feat(plugins): add similar songs retrieval functions and improve duration consistency (#4933)

* feat: add duration filtering for similar songs matching

Signed-off-by: Deluan <deluan@navidrome.org>

* test: refactor expectations for similar songs in provider matching tests

Signed-off-by: Deluan <deluan@navidrome.org>

* feat(plugins): add functions to retrieve similar songs by track, album, and artist

Signed-off-by: Deluan <deluan@navidrome.org>

* fix(plugins): support uint32 in ndpgen

Signed-off-by: Deluan <deluan@navidrome.org>

* fix(plugins): update duration field to use seconds as float instead of milliseconds as uint32

Signed-off-by: Deluan <deluan@navidrome.org>

* fix: add helper functions for Rust's skip_serializing_if with numeric types

Signed-off-by: Deluan <deluan@navidrome.org>

* feat(provider): enhance track matching logic to fallback to title match when duration-filtered tracks fail

---------

Signed-off-by: Deluan <deluan@navidrome.org>

plugins/cmd/ndpgen/internal/generator.go

@@ -568,6 +568,18 @@ func skipSerializingFunc(goType string) string {
 		return "String::is_empty"
 	case "bool":
 		return "std::ops::Not::not"
+	case "int32":
+		return "is_zero_i32"
+	case "uint32":
+		return "is_zero_u32"
+	case "int64":
+		return "is_zero_i64"
+	case "uint64":
+		return "is_zero_u64"
+	case "float32":
+		return "is_zero_f32"
+	case "float64":
+		return "is_zero_f64"
 	default:
 		return "Option::is_none"
 	}