fix: qualified wildcard column recognition

[reata]

Closes #423

[codecov]

Codecov Report

Merging #430 (13d1197) into master (bff222c) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master     #430   +/-   ##
=======================================
  Coverage   99.54%   99.54%           
=======================================
  Files          41       41           
  Lines        1972     1987   +15     
=======================================
+ Hits         1963     1978   +15     
  Misses          9        9           

Files Changed	Coverage Δ
.../parser/sqlfluff/extractors/dml_merge_extractor.py	100.00% <100.00%> (ø)
sqllineage/core/parser/sqlfluff/models.py	100.00% <100.00%> (ø)
sqllineage/core/parser/sqlfluff/utils.py	100.00% <100.00%> (ø)