Make flags use full names as per convention

A future update will allow for prefix-only matching separately.
For now, this is done to reduce ambiguity and allow for more flags to
be defined with no conflicts.

src/main/java/seedu/address/logic/parser/CliSyntax.java

@@ -5,11 +5,11 @@
  */
 public class CliSyntax {
 
-    /* Prefix definitions */
-    public static final Flag FLAG_NAME = new Flag("n");
-    public static final Flag FLAG_PHONE = new Flag("p");
-    public static final Flag FLAG_EMAIL = new Flag("e");
-    public static final Flag FLAG_ADDRESS = new Flag("a");
-    public static final Flag FLAG_TAG = new Flag("t");
+    /* Flag definitions */
+    public static final Flag FLAG_NAME = new Flag("name");
+    public static final Flag FLAG_PHONE = new Flag("phone");
+    public static final Flag FLAG_EMAIL = new Flag("email");
+    public static final Flag FLAG_ADDRESS = new Flag("addr");
+    public static final Flag FLAG_TAG = new Flag("tag");
 
 }