Methods to directly add rows and cols to highs model

[mmghannam]

No description provided.

[lovasoa]

looks good. Two small things: can we make it very obvious in the doc comments which methods can panic, and under which circumstances ?

Can we add asserts to the tests that check that the right values were added ? And also check the error cases of the try_* functions.

[mmghannam]

looks good. Two small things: can we make it very obvious in the doc comments which methods can panic, and under which circumstances ?

I added a panics section to the docs of the methods that can panic.
The circumstances that they can panic are not in the documentation, I took a look at the highs code; it seems there are many cases but I think some checks are irrelevant here because of the way we call the underlying highs function.

Can we add asserts to the tests that check that the right values were added ? And also check the error cases of the try_* functions.

I'm not sure how to do that without implementing get_cols() and get_rows() methods too. But I added an extra assert for the solution value.

[lovasoa]

Godd for me, thanks @mmghannam !