ARROW-11356: [Rust] Add method to PrimitiveArray::from_value to efficiently create an Array from a value

[Dandandan]

In DataFusion (and probably this would pop up in more use cases) we want to efficiently create an array with n items with the same value (instead of creating it from a Vec of values or iterator).

As discussed in here:
#9293

[github-actions]

https://issues.apache.org/jira/browse/ARROW-11356

[jorgecarleitao]

Do you see any difference between this one and using the iterator? I would expect them to perform equally well, since both are using push.

[Dandandan]

@jorgecarleitao I agree, it makes more sense to wait until this is faster and for now use the iterator for this case (even if it is slightly more verbose).
I think at some point this version could be specialized to use (the soon stable) slice.fill though, which I expect would be faster than using an iterator.

[Dandandan]

Creating an null array with known size might be another that might come up in the future, but I am witholding that until it is supported by some use case.