[FW][FIX] functions: allow to match empty cells

[fw-bot]

Description:

description of this task, what is implemented and why it is implemented that way.

Task: : 4023057

review checklist

• [ ] feature is organized in plugin, or UI components
• [ ] support of duplicate sheet (deep copy)
• [ ] in model/core: ranges are Range object, and can be adapted (adaptRanges)
• [ ] in model/UI: ranges are strings (to show the user)
• [ ] undo-able commands (uses this.history.update)
• [ ] multiuser-able commands (has inverse commands and transformations where needed)
• [ ] new/updated/removed commands are documented
• [ ] exportable in excel
• [ ] translations (_t("qmsdf %s", abc))
• [ ] unit tested
• [ ] clean commented code
• [ ] track breaking changes
• [ ] doc is rebuild (npm run doc)
• [ ] status is correct in Odoo

Forward-Port-Of: odoo/o-spreadsheet#4618 Forward-Port-Of: odoo/o-spreadsheet#4580

[robodoo]

[fw-bot]

This PR targets saas-17.3 and is part of the forward-port chain. Further PRs will be created up to master.

More info at https://github.com/odoo/odoo/wiki/Mergebot#forward-port