compute_ctl: Add endpoint that allows setting role grants (#9395)

This PR introduces a `/grants` endpoint which allows setting specific
`privileges` to certain `role` for a certain `schema`.

Related to #9344 

Together these endpoints will be used to configure JWT extension and set
correct usage to its schema to specific roles that will need them.

---------

Co-authored-by: Conrad Ludgate <conradludgate@gmail.com>

libs/compute_api/src/privilege.rs

@@ -0,0 +1,35 @@
+#[derive(Debug, Clone, serde::Deserialize, serde::Serialize)]
+#[serde(rename_all = "UPPERCASE")]
+pub enum Privilege {
+    Select,
+    Insert,
+    Update,
+    Delete,
+    Truncate,
+    References,
+    Trigger,
+    Usage,
+    Create,
+    Connect,
+    Temporary,
+    Execute,
+}
+
+impl Privilege {
+    pub fn as_str(&self) -> &'static str {
+        match self {
+            Privilege::Select => "SELECT",
+            Privilege::Insert => "INSERT",
+            Privilege::Update => "UPDATE",
+            Privilege::Delete => "DELETE",
+            Privilege::Truncate => "TRUNCATE",
+            Privilege::References => "REFERENCES",
+            Privilege::Trigger => "TRIGGER",
+            Privilege::Usage => "USAGE",
+            Privilege::Create => "CREATE",
+            Privilege::Connect => "CONNECT",
+            Privilege::Temporary => "TEMPORARY",
+            Privilege::Execute => "EXECUTE",
+        }
+    }
+}