[AQUMV] Expose the function adjust view query and varno fix.

[avamingli]

Add new function aqumv_adjust_simple_query.
Make it external for other codes may use the same logic. It has two main functions:
Adjust view query, remove 'old' and 'new' rte for refresh, make it to be a valid query tree.
Fix varno after that rewrite.

Fix varnosyn, keep it with varno as we don't have syntactic one.

Authored-by: Zhang Mingli avamingli@gmail.com

fix #ISSUE_Number

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