test(Spreadsheet File Node): Unit tests (no-changelog) (#5385)

* ⚡️test setup

* ⚡️fix  'testData' implicitly has an 'any' type.

* ✅ test github action file binary data reading

* ✅ checking for output binary equality

* ✅ writing files to different formats

* ✅ reading spreadsheet with different options

* ⚡️improve workflow file path replacement

* 🐛 fixing string.at() not supported in node 14.

* 🐛 trying to fix github action test error

* ⚡ fix for empty binary

* ⚡ switch for binary test

* ⚡️test helpers now return/compare json and binary (if not empty))

* ⚡ removed commented console log

---------

Co-authored-by: Michael Kret <michael.k@radency.com>

packages/nodes-base/nodes/SpreadsheetFile/test/spreadsheet.csv

@@ -0,0 +1,3 @@
+A,B,C
+1,2,3
+4,5,6