[BUG] Unexpected alias maintenance in the new GOpt-based compilation stack

[BingqingLyu]

Describe the bug
In the new GOpt-based compilation stack, there exist some bugs in alias maintenance.

For example, on modern graph:

gremlin> g.V(1).outE("knows").as("here").has("weight", 1.0d).as("fake").inV().has("name", "josh").select("here")
{alias=here} not found; expected aliases are: [fake, _]

This is not as expected.

Another case, though is not occurred by alias maintenance, is:

gremlin> g.V().select("a").count()
{alias=a} not found; expected aliases are: [_]

while the expected output is "0".

[Xiaoli Zhou]

Compared to Gremlin's native implementation, we have type inference functionality, and we will directly throw an error for non-existent aliases.