add ALTER DATABASE to completion/commandcomplete

[wonk1132]

trival addition of the DB command ALTER DATABASE

[codecov-commenter]

Codecov Report

Merging #901 (fb74951) into main (22882c5) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main     #901   +/-   ##
=======================================
  Coverage   83.89%   83.90%           
=======================================
  Files         125      125           
  Lines        1757     1758    +1     
  Branches      211      212    +1     
=======================================
+ Hits         1474     1475    +1     
  Misses        283      283           

Impacted Files	Coverage Δ
...s/core/shared/src/main/scala/data/Completion.scala	100.00% <ø> (ø)
...d/src/main/scala/net/message/CommandComplete.scala	92.06% <100.00%> (+0.12%)	⬆️