Rsh/flagged enums for java snippets

[ramsessanchez]

Flagged Enum support for Java Snippets.

//Previously setting a flagged enum property would be generated as:
setProperty(EnumClass.Enum1, EnumClass.Enum2);
//This fix ensures that flagged enums are handled as sets so we generate the following instead:
setProperty(EnumSet.of(EnumClass.Enum1, EnumClass.Enum2));

Added a isFlagsEnum boolean property to the CodeProperty class in order to aid in generation. This also adds a check in the SnippetCodeGraph class in order to set this boolean in the CodeProperty instance it creates.

Also fixes a bug where sub-namespaces of models would be incorrectly generated on return types. Sub-namespaces need to be fully qualified to disambiguate.

//In the prior snippets return types of models, under the security namespace for example, would be shown as:
security.Alert result = graphClient.something().get();
//The fix ensures that model subnamespaces are fully qualified so now we generate:
com.microsoft.graph.models.security.Alert result = graphClient.something().get();

Latest raptor run shows 94% pass rate:
https://microsoftgraph.visualstudio.com/Graph%20Developer%20Experiences/_build/results?buildId=125851&view=ms.vss-test-web.build-test-results-tab

Microsoft Reviewers: Open in CodeFlow

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
1 Code Smell

90.7% Coverage
0.0% Duplication

[andrueastman]

👍🏼