Goto Def Improvements, Merge Stmt Support

Added

• ide: goto def support for merge (#826),(#825)
• ide: goto def truncate, lock, vacuum, alter table column, refresh (#823)
• ide: document symbol support for create view (#807)
• ide: goto def create/alter/drop server (#821)
• ide: goto def foreign tables (#820)
• ide: use previous token in more cases of punctuation (#819)
• ide: support hover with * in queries (#818)
• ide: goto def support for references column constraints & select t.* from t; (#817)
• ide: support find references for join using clause (#816)
• ide: goto def using clause in join (#815)
• ide: goto def for tablespace (#814)
• ide: better goto def with create table (#813)
• ide: mat view goto def/hover, agg/procedure/mat view doc symbols (#812)
• ide: better goto def support for types (#811)
• ide: composite field goto def & hover (#810)
• ide: document symbol support for CTEs (#806)
• ide: hover for views (#804)
• ide: goto def with create view (#802)
• vscode: restart server command (#808)

Fixed

• ide: fix column name for special cased functions (#824)
• playground: fix dupe hover results in editor (#805)