Introduced value objects for heartrate, cadence, and power.

Fixes #896.

src/main/java/de/dennisguse/opentracks/data/models/Cadence.java

@@ -0,0 +1,43 @@
+package de.dennisguse.opentracks.data.models;
+
+import androidx.annotation.NonNull;
+
+import java.util.Objects;
+
+public class Cadence {
+
+    public static Cadence of(float value) {
+        return new Cadence(value);
+    }
+
+    private final float value;
+
+    private Cadence(float value) {
+        this.value = value;
+    }
+
+    public float getRPM() {
+        return value;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Cadence cadence = (Cadence) o;
+        return Float.compare(cadence.value, value) == 0;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(value);
+    }
+
+    @NonNull
+    @Override
+    public String toString() {
+        return "Cadence{" +
+                "value=" + value + " rpm" +
+                '}';
+    }
+}