Support SnapshotDependency full options

[cvbarros]

Currently, SnapshotDependency is created with default UI options. This issue is to add support for fully configuring all UI options when adding a snapshot dependency to a build configuration.

[cvbarros]

In addition, SnapshotDependency does not encapsulate "magic strings" properly, requiring the external SDK user to acknowledge inner workings on how the TeamCity API operates.

We need to also implement encapsulation as done with in artifact_dep_options.go