3.0 support nowait grammar

[cfzjywxk]

What problem does this PR solve?

cherry-pick #582 to release 3.0

the tidb related cherry-pick is link

What is changed and how it works?

Check List

Tests

• Unit test

Code changes

• Has exported function/method change
• Has exported variable/fields change

Side effects

Related changes

• Need to update the documentation
• Need to be included in the release note

[jackysp]

LGTM

[codecov]

Codecov Report

Merging #616 into release-3.0 will decrease coverage by 0.01%.
The diff coverage is 0%.

@@               Coverage Diff               @@
##           release-3.0     #616      +/-   ##
===============================================
- Coverage        50.99%   50.97%   -0.02%     
===============================================
  Files               31       31              
  Lines             6844     6846       +2     
===============================================
  Hits              3490     3490              
- Misses            3005     3007       +2     
  Partials           349      349

Impacted Files	Coverage Δ
parser.go	70.58% <ø> (ø)	⬆️
misc.go	96.42% <ø> (ø)	⬆️
ast/util.go	27.27% <0%> (ø)	⬆️
ast/dml.go	40.41% <0%> (-0.07%)	⬇️
ast/functions.go	70.56% <0%> (ø)	⬆️

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[coocood]

LGTM