Add Flatpak packaging for iDRAC6 console

- Manifest, desktop entry, metainfo, icon
- Direct Java launch (no javaws/IcedTea-Web)
- Bundles avctKVM.jar and native .so libs
- Parses JNLP for connection parameters
- sign-idrac.sh helper script

.gitignore

@@ -0,0 +1,5 @@
+*.tar.gz
+*.zip
+build-dir/
+.flatpak-builder/
+idrac-libs/