Updated Document entity to work with sourceId instead of callId

src/main/java/net/gepafin/tendermanagement/enums/DocumentSourceTypeEnum.java

@@ -0,0 +1,17 @@
+package net.gepafin.tendermanagement.enums;
+
+public enum DocumentSourceTypeEnum {
+    CALL("CALL"),
+
+    APPLICATION("APPLICATION");
+
+    private String value;
+
+    DocumentSourceTypeEnum(String value) {
+        this.value = value;
+    }
+
+    public String getValue() {
+        return value;
+    }
+}