Add metrics API

Defines MetricsData, MetricsReport and MetricsManager classes
so client xApps can generate and send reports via RMR.

Issue-ID: RIC-381
Signed-off-by: Lott, Christopher (cl778h) <cl778h@att.com>
Change-Id: I46890db2e9fedd007412cb480f592d059687ccf8
diff --git a/.gitignore b/.gitignore
index c86c4b7..1a9a867 100644
--- a/.gitignore
+++ b/.gitignore
@@ -114,3 +114,6 @@
 .project
 .pydevproject
 .settings/
+
+# VS Code
+.vscode/