fix unsupported breakpoint at method entry/exit or class (#129)

* Add location type check on breakpoint

Add location type check to avoid breakpoint on method/field which will never be hit in current implementation.

* fix breakpoint pos

update lines to the next line which is valid for breakpoint

* 1. add the logic to avoid duplicate install breakpoint when updated breakpoint lines have duplicate lines.

* revert unneeded change.

* removes invalid breakpoint

* fix checkstyle hint.

* Update typo in javadoc

* remove useless if condition

* remove tailing spaces.

* update javadoc

* revert the code to modify line numbers because in vscode, the action to set breakpoint will not report to our lang server immediately

* revert changes.

com.microsoft.java.debug.plugin/src/main/java/com/microsoft/java/debug/plugin/internal/JdtSourceLookUpProvider.java

@@ -150,7 +150,8 @@ public class JdtSourceLookUpProvider implements ISourceLookUpProvider {
                 ValidBreakpointLocationLocator locator = new ValidBreakpointLocationLocator(astUnit, lines[i], true, true);
                 astUnit.accept(locator);
                 // When the final valid line location is same as the original line, that represents it's a valid breakpoint.
-                if (lines[i] == locator.getLineLocation()) {
+                // Add location type check to avoid breakpoint on method/field which will never be hit in current implementation.
+                if (lines[i] == locator.getLineLocation() && locator.getLocationType() == ValidBreakpointLocationLocator.LOCATION_LINE) {
                     fqns[i] = locator.getFullyQualifiedTypeName();
                 }
             }