feat: Add boundary_group data source

[moduli]

This PR adds a boundary_group data source

data "boundary_group" "global_group" {
  name = "admin"
}

data "boundary_group" "org_group" {
  name     = "username"
  scope_id = data.boundary_scope.org.id
}

Test

resource "boundary_user" "user1" {
  name     = "user1"
  scope_id = "global"
}

resource "boundary_user" "user2" {
  name     = "user2"
  scope_id = "global"
}

resource "boundary_group" "group" {
  name       = "group"
  scope_id   = "global"
  member_ids = [boundary_user.user1.id, boundary_user.user2.id]
}

data "boundary_group" "group" {
  depends_on = [boundary_group.group]
  name       = "group"
}

output "group" {
  value = data.boundary_group.group
}


Outputs:

group = {
  "description" = ""
  "id" = "g_WlBSAYpsn3"
  "member_ids" = toset([
    "u_oPPhtdmDSu",
    "u_qDLvPFPCWS",
  ])
  "name" = "group"
  "scope" = tolist([
    {
      "description" = "Global Scope"
      "id" = "global"
      "name" = "global"
      "parent_scope_id" = ""
      "type" = "global"
    },
  ])
  "scope_id" = "global"
}

[grantorchard]

Excited for this one! Just had a need for a group datasource and decided to quickly check if someone had started work on it already 👍

[louisruch]

A couple of minor comments but otherwise this LGTM