feat: Create provisioner abstraction (#12)

* feat: Create provisioner abstraction

Creates a provisioner abstraction that takes prior art from the Terraform plugin system. It's safe to assume this code will change a lot when it becomes integrated with provisionerd.

Closes #10.

* Ignore generated files in diff view

* Check for unstaged file changes

* Install protoc-gen-go

* Use proper drpc plugin version

* Fix serve closed pipe

* Install sqlc with curl for speed

* Fix install command

* Format CI action

* Add linguist-generated and closed pipe test

* Cleanup code from comments

* Add dRPC comment

* Add Terraform installer for cross-platform

* Build provisioner tests on Linux only

scripts/check_unstaged.sh

@@ -0,0 +1,24 @@
+#!/bin/bash
+
+set -euo pipefail
+
+FILES="$(git ls-files --other --modified --exclude-standard)"
+if [[ "$FILES" != "" ]]; then
+    mapfile -t files <<<"$FILES"
+
+    echo "The following files contain unstaged changes:"
+    echo
+    for file in "${files[@]}"; do
+        echo "  - $file"
+    done
+    echo
+
+    echo "These are the changes:"
+    echo
+    for file in "${files[@]}"; do
+        git --no-pager diff "$file"
+    done
+    exit 1
+fi
+
+exit 0