I am trying to find implementations of any statistical method to test whether a sample is unimodal or multimodal distributed.

From Wikipedia Multimodal Distribution, you can find multiple example of such tests. In particular:

An implementation of the dip test is available for the R programming language.[56] The p-values for the dip statistic values range between 0 and 1. P-values less than 0.05 indicate significant multimodality and p-values greater than 0.05 but less than 0.10 suggest multimodality with marginal significance [57].

Is there anything like this in julia?