[Dataset] Move MRPC dataset to API

[eric-haibin-lin]

Description

Download the MRPC dataset hosted by the gluebenchmark.

Checklist

Essentials

• PR's title starts with a category (e.g. [BUGFIX], [MODEL], [TUTORIAL], [FEATURE], [DOC], etc)
• Changes are complete (i.e. I finished coding on this PR)
• All changes have test coverage
• Code is well-documented

Changes

• Feature1, tests, (and when applicable, API doc)
• Feature2, tests, (and when applicable, API doc)

Comments

• If this change is a backward incompatible change, why must this change be made.
• Interesting edge cases to note here

[codecov]

Codecov Report

❗ No coverage uploaded for pull request head (mrpc_dataset@60d1e6b). Click here to learn what that means.
The diff coverage is n/a.

[codecov]

Codecov Report

Merging #780 into master will decrease coverage by 8.66%.
The diff coverage is 96.49%.

@@            Coverage Diff             @@
##           master     #780      +/-   ##
==========================================
- Coverage    90.3%   81.63%   -8.67%     
==========================================
  Files          64       64              
  Lines        6238     6295      +57     
==========================================
- Hits         5633     5139     -494     
- Misses        605     1156     +551

Impacted Files	Coverage Δ
src/gluonnlp/data/glue.py	96.83% <96.49%> (-1.95%)	⬇️
src/gluonnlp/model/train/cache.py	26.19% <0%> (-71.43%)	⬇️
src/gluonnlp/model/train/language_model.py	42.04% <0%> (-55.12%)	⬇️
src/gluonnlp/embedding/evaluation.py	41.8% <0%> (-54.1%)	⬇️
src/gluonnlp/data/batchify/language_model.py	44.03% <0%> (-52.3%)	⬇️
src/gluonnlp/model/translation.py	20.63% <0%> (-50.8%)	⬇️
src/gluonnlp/model/language_model.py	50.38% <0%> (-49.62%)	⬇️
src/gluonnlp/model/bert.py	70.28% <0%> (-28.99%)	⬇️
src/gluonnlp/data/translation.py	73.64% <0%> (-26.36%)	⬇️
src/gluonnlp/model/train/__init__.py	75% <0%> (-25%)	⬇️
... and 14 more

[mli]

Job PR-780/1 is complete.
Docs are uploaded to http://gluon-nlp-staging.s3-accelerate.dualstack.amazonaws.com/PR-780/1/index.html

[mli]

Job PR-780/2 is complete.
Docs are uploaded to http://gluon-nlp-staging.s3-accelerate.dualstack.amazonaws.com/PR-780/2/index.html

[mli]

Job PR-780/3 is complete.
Docs are uploaded to http://gluon-nlp-staging.s3-accelerate.dualstack.amazonaws.com/PR-780/3/index.html