NuGet - add allowInsecureConnections attribute to config

[EyalDelarea]

• All tests have passed. If this feature is not already covered by the tests, new tests have been added.

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Allows the user to set allowInsecureConnections in NuGet config file.

  <packageSources>
    <add key="JFrogCli" value="%s" protocolVersion="%s" **allowInsecureConnections**="%v"/>
  </packageSources>

The latest .NET 6 release introduces changes to NuGet that now restrict the use of insecure connections for package sources unless a specific flag is enabled.

This update resolves the failing tests by adding the required flag for cases where it is necessary. This flag is primarily intended for testing purposes to allow use with local sources and should not be enabled in production environments.

For the tests this flag is set to true.
If you user would like to overwrite this flag, it can be done via the nuget.AllowInsecureConnections prop.