[RFC] : add C implementations for `@stdlib/stats/base/ndarray` packages (tracking issue)

### Description

This RFC proposes adding C implementations to all `@stdlib/stats/base/ndarray` packages that are currently missing them. The purpose of this issue is to serve as a tracking issue for adding these C implementations.

### Packages

#### Double-Precision

- [ ] dcovarmtk #15219
- [ ] dcumax #14921
- [ ] dcumaxabs #15144
- [ ] dcumin #15119
- [ ] dcuminabs #15145
- [ ] dmaxabssorted #14882
- [ ] dmeanstdev #15045
- [x] dmediansorted #13912
- [ ] dminsorted #14537
- [x] dmskmax #14419
- [ ] dmskmaxabs #14262
- [ ] dmskmin #14840
- [ ] dmskrange #14841
- [x] dnanmax #14360
- [ ] dnanmaxabs #14409
- [x] dnanmean #14049
- [x] dnanmeanors #14053
- [x] dnanmeanpn #14120
- [ ] dnanmeanpw #14177
- [x] dnanmeanwd #14225
- [x] dnanmidrange #14279
- [x] dnanmin #14297
- [x] dnanminabs #14356
- [ ] dnanmskmax #14844
- [ ] dnanmskmaxabs #14977
- [ ] dnanmskmin #14978
- [ ] dnanmskminabs #14979
- [ ] dnanmskrange #14980
- [x] dnanrange #14470
- [x] dnanrangeabs #14475
- [ ] dnanstdev #14721
- [ ] dnanstdevch #14724
- [ ] dnanstdevpn #14723
- [ ] dnanvariance #15069
- [x] drange #14523
- [x] dstdev #14636
- [x] dstdevch #14655
- [x] dstdevpn #14711
- [x] dstdevtk #14712
- [x] dstdevwd #14713
- [x] dstdevyc #14714
- [x] dvariance #14616
- [x] dvariancech #14772
- [x] dvariancepn #14792
- [x] dvariancetk #14794
- [x] dvariancewd #14795
- [x] dvarianceyc #14796
- [ ] dztest
- [ ] dztest2

#### Single-Precision

- [ ] scovarmtk #15239
- [ ] scumax #15167
- [ ] scumaxabs #15169
- [ ] scumin #15170
- [ ] scuminabs #15168
- [ ] sdsmean #15185
- [ ] sdsmeanors #15186
- [ ] sdsnanmeanors #15187
- [ ] smaxabssorted #15267
- [x] smean #10090
- [x] smeankbn #14604
- [x] smeankbn2 #13977
- [x] smeanli #14017
- [x] smeanlipw #14605
- [ ] smeanors #14070
- [ ] smeanpn #14176
- [ ] smeanpw #10389
- [ ] smeanwd #14237
- [ ] smediansorted #15270
- [ ] sminsorted #14358
- [ ] smskmax #14602
- [ ] smskmaxabs #14624
- [ ] smskmidrange #15215
- [ ] smskmin #14632
- [ ] smskrange #14725
- [ ] snanmaxabs #14477
- [ ] snanmean #14562
- [ ] snanmeanors #14587
- [ ] snanmeanpn #14628
- [ ] snanmeanwd #14627
- [ ] snanmidrange https://github.com/stdlib-js/stdlib/pull/15096
- [x] snanmin #14305
- [ ] snanminabs #14335
- [ ] snanmskmax #14758
- [ ] snanmskmaxabs #15161
- [ ] snanmskmidrange #15199
- [ ] snanmskmin https://github.com/stdlib-js/stdlib/pull/15103
- [ ] snanmskminabs https://github.com/stdlib-js/stdlib/pull/15133
- [ ] snanmskrange #14757
- [ ] sstdev #14718
- [ ] sstdevch #14815
- [ ] sstdevpn #14881
- [ ] sstdevtk #14885
- [ ] sstdevwd #14891
- [ ] sstdevyc #15003
- [x] svariance #14618
- [x] svariancech #15008
- [ ] svariancepn #15009
- [ ] svariancetk #15030
- [ ] svariancewd #15031
- [ ] svarianceyc #15032
- [ ] sztest
- [ ] sztest2

### Related Issues

None.

### Questions

No.

### Other

No.

### Checklist

- [X] I have read and understood the [Code of Conduct](https://github.com/stdlib-js/stdlib/blob/develop/CODE_OF_CONDUCT.md).
- [X] Searched for existing issues and pull requests.
- [X] The issue name begins with `RFC:`.

Start with one unchecked package in the Double-Precision or Single-Precision list and read its linked issue; this tracking RFC names no files or tests. Done means the selected package has its missing C implementation added and its checklist entry can be marked complete.

Vom Indexierungsmodell aus dem Issue-Text verfasst.