Fix issue: sort order keyword is case sensitive

[chloe-zh]

Issue #, if available:
#852

Description of changes:

• Replaced the sort order keyword to upper case when collecting the query information in QuerySpecification
• Added tests

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov]

Codecov Report

Merging #853 (8834af5) into develop (42d79c2) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             develop     #853   +/-   ##
==========================================
  Coverage      99.85%   99.85%           
  Complexity      2115     2115           
==========================================
  Files            214      214           
  Lines           4729     4729           
  Branches         308      308           
==========================================
  Hits            4722     4722           
  Misses             5        5           
  Partials           2        2           

Impacted Files	Coverage Δ	Complexity Δ
...rch/sql/sql/parser/context/QuerySpecification.java	100.00% <100.00%> (ø)	15.00 <0.00> (ø)

---

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 42d79c2...8834af5. Read the comment docs.

[dai-chen]

Thanks for the fix!