New k-point interface

[brainandforce]

The KPoint data type wraps an SVector and associates an integer weight with it. The KPointMesh type replaces the old KPointList and KPointGrid types, and stores both an explicitly generated list of k-points and the integer matrix used to generate them.

I still need to change over HKLData to use KPoint instead of an SVector.

[codecov[bot]]

Codecov Report

Patch coverage: 60.00% and project coverage change: +0.53 :tada:

Comparison is base (a7f8946) 39.77% compared to head (d2a22f2) 40.30%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #156 +/- ## ========================================== + Coverage 39.77% 40.30% +0.53% ========================================== Files 16 16 Lines 1315 1325 +10 ========================================== + Hits 523 534 +11 + Misses 792 791 -1 ``` | [Impacted Files](https://codecov.io/gh/brainandforce/Electrum.jl/pull/156?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Brandon+Flores) | Coverage Δ | | |---|---|---| | [src/Electrum.jl](https://codecov.io/gh/brainandforce/Electrum.jl/pull/156?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Brandon+Flores#diff-c3JjL0VsZWN0cnVtLmps) | `0.00% <ø> (ø)` | | | [src/software/vasp.jl](https://codecov.io/gh/brainandforce/Electrum.jl/pull/156?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Brandon+Flores#diff-c3JjL3NvZnR3YXJlL3Zhc3Auamw=) | `11.92% <0.00%> (ø)` | | | [src/data/reciprocalspace.jl](https://codecov.io/gh/brainandforce/Electrum.jl/pull/156?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Brandon+Flores#diff-c3JjL2RhdGEvcmVjaXByb2NhbHNwYWNlLmps) | `21.48% <55.88%> (+5.69%)` | :arrow_up: | | [src/software/abinit.jl](https://codecov.io/gh/brainandforce/Electrum.jl/pull/156?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Brandon+Flores#diff-c3JjL3NvZnR3YXJlL2FiaW5pdC5qbA==) | `46.24% <100.00%> (+0.48%)` | :arrow_up: | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Brandon+Flores). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Brandon+Flores)

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[brainandforce]

Just added the changes for HKLData.