Adds cohort access to SNP and CNV frequency methods

`gene_cnv_frequencies` - fixes pandas fragment warning

Upgrade `cohorts_analysis` to 20210927

updates docs for 0.12.0 release

Co-authored-by: Alistair Miles <[email protected]>

Bug fix and doc update for 0.12.1

* wip amin1

* wip and refactoring

* wip amin1 first pass done

* wip multiple contigs

* multiple contigs

* fix docstrings

* release notes

* bump version

Update  `cohorts_analysis` to latest version

v0.15.0 release

* Add variance vars to test_cnv_hmm

* Add variance vars to _cnv_hmm_dataset

* sample_sets multi releases

* wip multi releases

* wip sample_sets rework

* wip test multiple releases

* tidy

* remove test skips

* simplify handling of multiple sample sets

* simplify sample_sets normalisation

* add test for chunks pass through

* fix recursion

* fix comment

* upgrade ci matrix

* fix version strings

* attempt to support py 3.10

* update dev deps

* back off py 3.10

* update dev deps

* simplify species calls analysis parameter

* consolidate default analyses

* modify species column names

* fix species columns

* fix constant names

* simplify

* add effects to allele frequencies

* fix whitespace

* Add hidden vscode folder to gitignore

* Remove cached pyc

* Support genomic regions - SNPs

* Refactor _resolve_region() and renaming

* Move region resolving to private methods for consistency

(cherry picked from commit 5eb2fbc)

* Add tests for locate_region()

(cherry picked from commit 1723bfa)

* un-fragments snp_allele_freq df

* defragmentioned

* use consistent release identifiers in public API

* default to GCS URL

* add Ag3 reprs

* tidy up release handling

* fix tests

* normalise analysis parameter naming

Add "frq_" to columns in frequency generating methods