refactor(cli): introduce the migration-runner helper for less code duplication and fewer return paths

Thanks to the migration-runner the "up" and "list" commands are now very similar code wise

packages/cli/src/collect-migrations.ts

@@ -0,0 +1,33 @@
+import {
+  type MigrationHistoryEntry,
+  type MigrationMetadata,
+  type MigrationMetadataFinished,
+} from '@emigrate/plugin-tools/types';
+import { toMigrationMetadata } from './to-migration-metadata.js';
+import { getMigrations as getMigrationsOriginal } from './get-migrations.js';
+
+export async function* collectMigrations(
+  cwd: string,
+  directory: string,
+  history: AsyncIterable<MigrationHistoryEntry>,
+  getMigrations = getMigrationsOriginal,
+): AsyncIterable<MigrationMetadata | MigrationMetadataFinished> {
+  const allMigrations = await getMigrations(cwd, directory);
+  const seen = new Set<string>();
+
+  for await (const entry of history) {
+    const index = allMigrations.findIndex((migrationFile) => migrationFile.name === entry.name);
+
+    if (index === -1) {
+      continue;
+    }
+
+    yield toMigrationMetadata(entry, { cwd, directory });
+
+    seen.add(entry.name);
+  }
+
+  yield* allMigrations.filter((migration) => !seen.has(migration.name));
+
+  seen.clear();
+}