Refactor/sdp structure cleanup

[NimaSarajpoor]

This is to address PR 1 described in this comment. Have copied the corresponding notes below:

1. Create a new sdp.py file
2. Move _sliding_dot_product to sdp.py and call it _njit_sliding_dot_product
3. Removing the core._sliding_dot_product altogether (currently, you are keeping both and calling one from the other. This is a bad idea)
4. Replace all (three) references to core._sliding_dot_product with sdp._njit_sliding_dot_product
5. Update move tests from tests/test_core.py to tests/test_sdp.py
6. Add an sdp._sliding_dot_product that simply calls _njit_sliding_dot_product (complexity gets added in future PRs)
7. Make core.sliding_dot_product = sdp._sliding_dot_product

[gitnotebooks]

Review these changes at https://app.gitnotebooks.com/stumpy-dev/stumpy/pull/1126

[NimaSarajpoor]

@seanlaw
We also need to modify Tutorial_DiscordMERLIN.ipynb as it uses core._sliding_dot_product, and need to run the whole notebook again. However, the problem is that the notebook loads data from directories that do not exist. Also, the data provided by MERLIN webpage is not accessible anymore.

[seanlaw]

@NimaSarajpoor Looking good! This is much easier to track

[NimaSarajpoor]

We also need to modify Tutorial_DiscordMERLIN.ipynb as it uses core._sliding_dot_product, and need to run the whole notebook again. However, the problem is that the notebook loads data from directories that do not exist. Also, the data provided by MERLIN webpage is not accessible anymore.

I've also noticed that the code in the notebook requires some updates. For instance, in the notebook, I see:

T, M_T, Σ_T = core.preprocess(ts, m)

However, this function in branch main now returns four values instead of three.

@seanlaw
This notebook is outdated. I think we should submit an issue for this, and address it later and separately.

[seanlaw]

This notebook is outdated. I think we should submit an issue for this, and address it later and separately.

I agree with that