[Feature] Add init_eval to evaluation hook

[dreamerlin]

1. Add start argument in xxEvalHook to indicate the start time for evaluation
2. Add prefix Epoch to indicate the current EvalHook is based on epochs

[codecov]

Codecov Report

Merging #216 into master will increase coverage by 0.56%.
The diff coverage is 84.21%.

@@            Coverage Diff             @@
##           master     #216      +/-   ##
==========================================
+ Coverage   84.40%   84.97%   +0.56%     
==========================================
  Files          87       87              
  Lines        5880     5910      +30     
  Branches      959      969      +10     
==========================================
+ Hits         4963     5022      +59     
+ Misses        744      705      -39     
- Partials      173      183      +10     

Flag	Coverage Δ
#unittests	84.97% <84.21%> (+0.56%)	⬆️

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

Impacted Files	Coverage Δ
mmaction/apis/train.py	19.04% <50.00%> (ø)
mmaction/core/evaluation/eval_hooks.py	57.02% <85.71%> (+39.44%)	⬆️
mmaction/core/evaluation/__init__.py	100.00% <100.00%> (ø)
mmaction/datasets/pipelines/augmentations.py	95.00% <0.00%> (+0.71%)	⬆️
mmaction/core/evaluation/accuracy.py	89.85% <0.00%> (+0.96%)	⬆️

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[dreamerlin]

Ping @innerlee

[dreamerlin]

It is OK now @innerlee

[innerlee]

for the renaming, have you searched through docs as well?

[dreamerlin]

for the renaming, have you searched through docs as well?

Oops, now it has been updated

[innerlee]

hope this rename does not cause trouble