Use symbolic name compilation if any explicit dependencies on existing resources are declared

[jeskew]

Is your feature request related to a problem? Please describe.
Resources are allowed to declare explicit dependencies (via the dependsOn property) on any resource, including existing resources. In symbolic name templates, this allows template authors to "gate" a resource deployment on whether a resource not included in the template exists (as requested in #10097); in non-symbolic name templates, however, the explicit dependency is silently dropped.

Describe the solution you'd like
If a template contains any explicit dependency on existing resources, Bicep should compile to a symbolic name template so that the dependency is retained in the ARM JSON template.