Allow adding new rows or columns on paste

[romanstetsyk]

Fixes issue #552.

Changes proposed in this pull request:

• Add a new attribute, allowGridSizeChangeOnPaste (which is false by default). If it's set to true and pasted data is bigger than the grid, new rows or columns will be created as needed. Please see the screen recording.

Screen.Recording.2023-04-06.at.23.05.47.mov

This is slow for big datasets because a) .addRow() calls .refresh() b) on each cell pasted .selectCell() is called. So there's plenty of room for optimization.

[ndrsn]

Great work @romanstetsyk, thanks so much! I have a few minor points, but I really appreciate the tests you've written in addition to the new functionality — really makes things easier to merge :)

[ndrsn]

Should we not be using self.getSchema() here? Or rather:

const schema = self.getSchema();

if (!schema[columnIndex]) {
  if (self.attributes.allowGridSizeChangeOnPaste) {
    const lastColSchema = schema[self.orders.columns[schema.length - 1]];
  }
  const newColSchema = {
    ...lastColSchema,
    name: `col${schema.length + 1}${Date.now()}`,
    title: ' ',
  };
  self.addColumn(newColSchema)
}

Also, two (three?) other points:

1. can we safely assume that the last column's schema is similar to the newly pasted column? What is you're pasting text and the previous existing column schema defines it as type: number ?
2. What is the purpose of the name including the current date? Do we even need to name the new column?
3. Why the empty title?