Issue:Creating band matrices #1160, implemented initial version

[Matoka26]

I've tried to implement an initial version for the from_bands method to construct a band matrix from some vectors. I ve tried that in order to learn Rust, I'm open to advices.
I am not sure how to compile the project so i could only test the logic inside a separate project.
Hope it can be helpful.

Approach:

• I only considered odd number of vectors, the middle one becoming the main diagonal, each from its left become under diagonal bands, each from right become over diagonal bands.
• The size of the resulting matrix is calculated as such: the length of the longest vector + the offset from the main diagonal
• Set the elements on the corresponding positions