fix(migrations): use migration file extension according to runtime

We need to use .ts only if we run inside ts-node
or other tools that use it. In all other cases, we need to
refer to the .js migration files.

Signed-off-by: David Mehren <git@herrmehren.de>

backend/src/utils/detectTsNode.ts

@@ -0,0 +1,20 @@
+/*
+ * SPDX-FileCopyrightText: 2018 Martin Adámek
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+/**
+ * Stolen from https://github.com/mikro-orm/mikro-orm/blob/20179ec839def5f8144e56f3a6bc89131f7e72a4/packages/core/src/utils/Utils.ts#L689
+ */
+export function detectTsNode(): boolean {
+  return (
+    process.argv[0].endsWith('ts-node') || // running via ts-node directly
+    // eslint-disable-next-line @typescript-eslint/ban-ts-comment
+    // @ts-ignore TS7053
+    !!process[Symbol.for('ts-node.register.instance')] || // check if internal ts-node symbol exists
+    !!process.env.TS_JEST || // check if ts-jest is used (works only with v27.0.4+)
+    process.argv.slice(1).some((arg) => arg.includes('ts-node')) || // registering ts-node runner
+    (require.extensions && !!require.extensions['.ts'])
+  ); // check if the extension is registered
+}