Fix an error in numeric cell types that occur after entering non-numeric values

[budnix]

Context

The PR fixes an error in numeric cell types that occur after entering non-numeric values like - 10000 (with spaces between -/+ sign).

How has this been tested?

I tested the changes locally, and I covered the fix with tests.

Types of changes

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

Related issue(s):

1. fixes https://github.com/handsontable/dev-handsontable/issues/1858

Affected project(s):

• [x] handsontable

Checklist:

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