added database crate, "settings" with migrations and queries, running migrations on web startup

crates/database/migrations/20230227133744_settings.down.sql

@@ -0,0 +1 @@
+drop table if exists settings;

crates/database/migrations/20230227133744_settings.up.sql

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+create table if not exists settings
+(
+    id            INTEGER not null primary key check ( id = 0 ),
+    created_at    TEXT    not null default CURRENT_TIMESTAMP,
+    updated_at    TEXT    not null default CURRENT_TIMESTAMP,
+    business_name TEXT,
+    business_logo BLOB
+);
+
+-- update "updated_at"
+create trigger if not exists settings_updated_at
+    after
+        update
+    on settings
+    for each row
+begin
+    update settings
+    set updated_at = CURRENT_TIMESTAMP
+    where id is NEW.id;
+end;