featureUtility installServerFeature fails when user feature is listed

[jjiwooLim]

Describe the bug
featureUtility installServerFeatures contains bugs when the user configures a product extension in their server.xml.
- e.g) <feature>myExt:userfeature-1.0</feature>

1. If the user feature file doesn't contain the following regex (Liberty version), \\d\\d\\.\\d\\.\\d\\.\\d\\.esa, the user feature will not be installed to the defined product extension. The user feature doesn't need to have the same version as the Liberty version.
2. The tool doesn't fetch the installed features properly.

Steps to Reproduce

featureUtility installServerFeatures --noCache --acceptLicense defaultServer

Error:

Resolving remote features. This process might take several minutes to complete.
[6/28/21 11:48:29:156 EDT] CWWKF1402E: The following features were not obtained: userFeature-1.0. Ensure that the features are valid.

• server.xml configuration

<featureManager>
      <feature>usr:userFeature-1.0</feature>
 </featureManager>

Diagnostic information:

• OpenLiberty Version: 21.0.0.11 and 21.0.0.12

Additional context
This will consider the use case where an application team creates a user feature that is pre-installed when the server package is created. In this case, users doesn't need to specify the featuresbom property and the installServerFeature should finish successfully.