Update types & db schema (#3)

* Update types & db schema

packages/cockroach/migrations/02_patch.sql

@@ -0,0 +1,13 @@
+CREATE TABLE IF NOT EXISTS patch
+(
+    id         INT8         NOT NULL DEFAULT unique_rowid(),
+    message_id UUID         NOT NULL,
+    content    TEXT         NOT NULL,
+    creator    VARCHAR(255) NOT NULL,
+    created    TIMESTAMPTZ  NOT NULL,
+
+    PRIMARY KEY (id),
+    FOREIGN KEY (message_id) REFERENCES message (id) ON DELETE CASCADE
+);
+
+CREATE INDEX idx_patch_message_id ON patch (message_id);