more array creation methods from numpy

[xnought]

Matching numpy, numjs would improved if numjs also had the following methods

• eye() https://numpy.org/devdocs/reference/generated/numpy.eye.html
• tri() https://numpy.org/devdocs/reference/generated/numpy.tri.html
• full https://numpy.org/devdocs/reference/generated/numpy.full.html
• ones_like() https://numpy.org/devdocs/reference/generated/numpy.ones_like.html
• zeros_like() https://numpy.org/devdocs/reference/generated/numpy.zeros_like.html
• full_like() https://numpy.org/devdocs/reference/generated/numpy.full_like.html

With methods to generate arrays and pick values (upper and lower triangular), numjs would become more powerful immediately.

I made this issue since I intend to implement these methods in numjs and make a PR or fork.