Improve plugins TS types

[budnix]

Context

The PR improves plugins TS types. The changes:

• Add TS typing test for the ManualRowResize and ManaulColumnResize plugins;
• Add TS typing test for the ManualColumnFreeze plugin;
• Improve TS typings for the AutoRowSize and AutoColumnSize plugins;
• Add TS typing test for the DragToScroll plugin;
• Improve TS typings for the ExportFile plugin;
• Improve TS typings for the BindRowsWithHeaders plugin;
• Improve TS typings for the ColumnSummary plugin;
• Add TS typing test for the MergeCells plugin;
• Add TS typing test for the MultipleSelectionHandles plugin;
• Add TS typing test for the NestedRows plugin;
• Add and improve TS typing for the PersistentState plugin;
• Add TS typing test for the Search plugin;
• Add TS typing test for the TrimRows plugin;
• Improve TS typings for the UndoRedo plugin;

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Affected project(s):

• handsontable

Checklist:

• I have reviewed the guidelines about Contributing to Handsontable and I confirm that my code follows the code style of this project.
• I have signed the Contributor License Agreement

[wszymanski]

Good to see tests also for plugins 🙂