test: Improve tests of `increase_order_utils` library.

[sparqet]

Description

Implement and improve tests of increase_order_utils library.

File: test/order/increase_order_utils.cairo.

Acceptance criteria

• Unit tests (nominal and failure) are implemented and passing.

[ftupas]

Hello, may I take this?

[sparqet]

assigned !

[Sk8erboi84]

Any updates ? @ftupas

[ftupas]

Hello, sorry for that, started to work on it but got a bit busy with personal stuff, will continue this weekend and get it to the finish line

[tevrat-aksoy]

I can take take this, if it is available