Implemented basic, deno KV backed, file service.

migrations/foo_001.sql

@@ -0,0 +1,21 @@
+CREATE TABLE file (
+    id            INTEGER PRIMARY KEY AUTOINCREMENT,
+    file_name     TEXT NOT NULL,
+    sha1          TEXT NOT NULL
+)
+
+CREATE TABLE file_to_blob(
+    id            INTEGER PRIMARY KEY AUTOINCREMENT,
+    file_id       INTEGER NOT NULL,
+    blob_id       INTEGER NOT NULL,
+
+    FOREIGN KEY (file_id) REFERENCES file (id),
+    FOREIGN KEY (blob_id) REFERENCES blob_ (id)
+)
+
+CREATE TABLE blob_ (
+    id            INTEGER PRIMARY KEY AUTOINCREMENT,
+    data          BLOB NOT NULL,
+    sha1          TEXT NOT NULL,
+)
+