Add some utility functions

Author: RISCfuture

Sources/SwiftMETAR/Common/Weather.swift

@@ -59,6 +59,11 @@ public struct Weather: Codable, Equatable, Sendable {
 
         /// Another "pseudo-intensity" for heavy phenomena in the vicinity.
         case vicinityHeavy = "+VC"
+        
+        /// `true` if this is an "in the vicinity" pseudo-intensity.
+        public var isVicinity: Bool {
+            self == .vicinity || self == .vicinityLight || self == .vicinityHeavy
+        }
     }
 
     /// Qualifiers for precipitation phenomena. Most are not applied to

Sources/SwiftMETAR/Remarks/Remark.swift

@@ -430,6 +430,11 @@ public enum Remark: Codable, Equatable, Sendable {
 
         /// The distance, in statute miles.
         public let distance: UInt
+        
+        /// The distance, as a measurement.
+        public var distanceMeasurement: Measurement<UnitLength> {
+            .init(value: Double(distance), unit: .miles)
+        }
     }
 
     /// A proximity from an observation station.