ci: [ATL-1640] add swiftlint

Megalinter doesnt work well with swiftlint. This issue has been reported in the ticket below.
While a solution is not provided we will go forward with having this swiftlint action and disable the
megalinter swiftlint process.
oxsecurity/megalinter#440

Author: goncalo-frade-iohk

.github/workflows/megalinter.yml

@@ -22,6 +22,14 @@ jobs:
           VALIDATE_ALL_CODEBASE: ${{ github.event_name == 'push' && github.ref == 'refs/heads/main' }}
           DISABLE: COPYPASTE,SPELL
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          DISABLE_LINTERS: SWIFT_SWIFTLINT
+
+      - name: SwiftLint
+        uses: norio-nomura/[email protected]
+        with:
+          args: --strict
+        env:
+          DIFF_BASE: ${{ github.base_ref }}
 
       - name: Archive production artifacts
         if: success() || failure()