Add qc to top level init

[ctuguinay]

This PR addresses the fact that qc doesn't exist in init and qc functions cannot be imported. Super small fix.

[codecov-commenter]

Codecov Report

Merging #1193 (a0c5e17) into dev (0bc534e) will decrease coverage by 56.79%. The diff coverage is 100.00%.

@@             Coverage Diff             @@
##              dev    #1193       +/-   ##
===========================================
- Coverage   77.04%   20.26%   -56.79%     
===========================================
  Files          67       67               
  Lines        5908     5908               
===========================================
- Hits         4552     1197     -3355     
- Misses       1356     4711     +3355     

Flag	Coverage Δ
unittests	20.26% <100.00%> (-56.79%)	:arrow_down:

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
echopype/__init__.py	100.00% <100.00%> (ø)

... and 50 files with indirect coverage changes

:mega: We’re building smart automated test selection to slash your CI/CD build times. Learn more

[ctuguinay]

Closing this since I'm now seemingly able to import qc functions without this addition.