Paste figures with spaces should either cut or ignore spaces

[HectorB-2020]

Expected behaviour

Numbers with spaces as a thousand separator such as 123 456 copied from different sources should not generate errors.
Ideally spaces should be either ignored and preserved or cut making 123 456 -> 123456

Actual behaviour

Numbers with spaces such as 123 456 copied from different sources produce errors "Malformed expression".
When spaces are manually deleted, the program successfully proceeds.

Steps to reproduce the behaviour

1. Start mate-calc.
2. Copy digits with space as a thousand separator like 123 456.
3. Paste them in the the program with Ctrl-V
4. Add + 25 Enter
5. Confirm error "Malformed expression".

MATE general version

1.26.0
1.24.0

Package version

mate-calc --version
mate-calc 1.26.0

mate-calc --version
mate-calc 1.24.0

Linux Distribution

Ubuntu 21.10
Ubuntu 20.04 LTS

Link to bugreport of your Distribution (requirement)

https://bugs.launchpad.net/ubuntu/+source/mate-calc/+bug/1964810