Add GetUint and GetUint64 method on gin.context

[kaiiak]

close #2432

[kaiiak]

@thinkerou @appleboy I recommit a pr, please review it, thanks.

[codecov]

Codecov Report

Merging #2487 into master will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #2487   +/-   ##
=======================================
  Coverage   98.72%   98.73%           
=======================================
  Files          41       41           
  Lines        2359     2367    +8     
=======================================
+ Hits         2329     2337    +8     
  Misses         17       17           
  Partials       13       13           

Impacted Files	Coverage Δ
context.go	98.12% <100.00%> (+0.03%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update b94d23d...1537b1c. Read the comment docs.

[thinkerou]

LGTM, thanks!