…rm functions (#16183)

Relates to #15977

Adds support for some functions in `tfparse` (only functions that do not
reference local files).
NOTE: for now, I'm importing trivy-iac. If we prefer to avoid a little
dependency, I can do a little copying instead.

(cherry picked from commit 4ba0b39)

…pace_tag defaults (#16303)

* chore(docs): update docs re workspace tag default values
* chore(coderdenttest): use random name instead of t.Name() in newExternalProvisionerDaemon
* fix(provisioner/terraform/tfparse): allow empty values in coder_workspace_tag defaults

(cherry picked from commit 76adde9)