parameter validation errors should happen in the wizard instead of the workspace build

[matifali]

Given a parameter with a choice, when creating a Workspace, if the user deletes the default value in the field, in this example from "0" to ""

data "coder_parameter" "home_data_disk_size" {
  type        = "number"
  name        = "Additional Home Data Volume Size"
  mutable     = true
  default     = 0
  validation {
    min       = 0
    max       = 2048
    monotonic = "increasing"
  }
}

You get this error when the Terraform runs:

Error: value "" is not a number
on .terraform/modules/platform_eng/data.tf line 487, in data "coder_parameter" "home_data_disk_size":
  487: data "coder_parameter" "home_data_disk_size" {

I believe this should be validated when in the wizard instead. Either that or provide something like a boolean attribute in the coder_parameter schema for an option like non_empty