Add benchmarks

[Saransh-cpp]

Description

Using Julia gives us the advantage of speed, hence adding some benchmarks would make sure that the speed doesn't go low. Add some benchmarks and also a new workflow to benchmark periodically and on a PR.

Motivation

The package should be fast, given that it is operating on 1000s of pixels.

Possible Implementation

BenchmarkTools.jl

Additional context

No response