use SQLDelight, remove ApiApps access from KeychainProvider

OpenKeychain/src/main/sqldelight/org/sufficientlysecure/keychain/ApiApps.sq

@@ -4,5 +4,23 @@ CREATE TABLE IF NOT EXISTS api_apps (
     package_signature BLOB
 );
 
-getAllowedKeys:
-SELECT
+insertApiApp:
+INSERT INTO api_apps (package_name, package_signature) VALUES (?, ?);
+
+selectAll:
+SELECT *
+    FROM api_apps;
+
+selectByPackageName:
+SELECT *
+    FROM api_apps
+    WHERE package_name = ?;
+
+deleteByPackageName:
+DELETE FROM api_apps
+    WHERE package_name = ?;
+
+getCertificate:
+SELECT package_signature
+    FROM api_apps
+    WHERE package_name = ?;