add custom operator support for number and integer

[thoys]

This PR adds support for extending the number / integer operators.

For example if you have a Vector3 class that could be multiplied with now this will work

---@class integer
---@operator mul(Vector3): Vector3

---@class number
---@operator mul(Vector3): Vector3

local shouldShowupAsAVector3 = 1.0 * Vector3.New(1,2,3);

[sumneko]

First of all, thank you for your PR. But I don't think this can work, the operator should be a part of Vector3 instead of integer or number, but the current design does not support it as the second operation. In addition, you need to add unit testing

[sumneko]

see #1371