Resolution improvement and extra_var in data

[jiangyi15]

Add extra_var in loading data.

data:
    extra_var:
          xx:
              default: 1
    data_xx: [files...]
    phsp_xx: [files...] 

Support resolution with cFit

Directly plot with resolution

data:  
    data_rec: [[file]...]
    phsp_rec: [[file]...] 

fit use data and phsp
plot use data_rec and phsp_rec with weights calculated though phsp.

[codecov-commenter]

Codecov Report

Merging #87 (9e066ac) into dev (4220537) will increase coverage by 0.07%.
The diff coverage is 87.80%.

@@            Coverage Diff             @@
##              dev      #87      +/-   ##
==========================================
+ Coverage   73.76%   73.83%   +0.07%     
==========================================
  Files         104      104              
  Lines       14595    14640      +45     
  Branches     2706     2717      +11     
==========================================
+ Hits        10766    10810      +44     
- Misses       3176     3177       +1     
  Partials      653      653              

Flag	Coverage Δ
unittests	73.83% <87.80%> (+0.07%)	⬆️

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

Files Changed	Coverage Δ
tf_pwa/data.py	75.84% <0.00%> (ø)
tf_pwa/config_loader/config_loader.py	63.88% <70.00%> (+0.22%)	⬆️
tf_pwa/config_loader/data.py	60.53% <73.91%> (+0.67%)	⬆️
tf_pwa/config_loader/plot.py	69.33% <100.00%> (+0.59%)	⬆️
tf_pwa/data_trans/helicity_angle.py	93.65% <100.00%> (+0.12%)	⬆️
tf_pwa/data_trans/test_helicity_angle.py	100.00% <100.00%> (ø)
tf_pwa/model/cfit.py	75.30% <100.00%> (+0.15%)	⬆️
tf_pwa/model/model.py	49.62% <100.00%> (+0.38%)	⬆️
tf_pwa/tests/test_full.py	100.00% <100.00%> (ø)