[NO-ISSUE][GRAPHIX] Refactoring AST body normalization.

Details:
  - No longer going through hoops to normalize a graph element body
    (we no longer follow the SQL++ AST rewriter way of normalizing view
    bodies).
  - Removing the IGraphExpr interface, this was never used.

Change-Id: I852bef041abb876cc2414b0d2b75e40411c60330
Reviewed-on: https://asterix-gerrit.ics.uci.edu/c/asterixdb-graph/+/16204
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Reviewed-by: Glenn Galvizo <ggalvizo@uci.edu>
24 files changed
tree: e203239054af00fe4a33eb3a7fe883e3cb7c2a4d
  1. .gitignore
  2. asterix-graphix/
  3. asterix-opt-bom/
  4. pom.xml