feat: add template_id and template_name to workspace data source

[sreya]

implements the TF portion of coder/coder#9149

[matifali]

@sreya, do template_id and template_name correspond to the template [name] and --name of the template if we see the context of coder templates push [name] --name=SOME_VERSION_NAME? I am asking this in the context of coder/coder#9318 (comment)

I'm concerned about if we are making the nomenclature around template names more fragmented here.

cc: @bpmct.

[sreya]

@matifali template_id points to the uuid of the template name points to the name of the template (as opposed to the name of the version)