InMemory: Improve indexing in server expression

[smitpatel]

InMemory: Improve indexing in server expression

Implement left join as client method to reduce complexity
To resolve the indexing issue stemming from #23934
Now all the projections are applied immediately to reshape the value buffer so that all our future bindings are always read value expressions which refers to a proper index.
In order to do this, we apply select for entity type with hierarchy to avoid entity check conditional expression.
For adding projection (through ReplaceProjectionMapping),

• For client projection, we apply a select and re-generate client projection as read values
• For projection mapping, we iterate the mappings, we apply a select and re-generate the mapping as read values
• If projection mapping is empty then we add a dummy 1 so that it becomes non-range-variable
  When applying projection, we generate a selector lambda to form a value buffer and replace all the expressions to read from new value buffer. Overall this solves the issue of having complex expressions to map or pull. This also removed PushDownIntoSubquery method.

In order to avoid the issue of indexes changing when generating join due to iterating projection mappings, we now also have projectionMappingExpressions which remembers the all expressions inside projectionMapping (which are all read value as we generated before). So now we don't need to iterate the mapping and we use the existing expressions directly. This keeps existing indexes.

Resolves #13561
Resolves #17539
Resolves #18194
Resolves #18435
Resolves #19344
Resolves #19469
Resolves #19667
Resolves #19742
Resolves #19967
Resolves #20359
Resolves #21677
Resolves #23360
Resolves #17537
Resolves #18394
Resolves #23934

[maumar]

[ghost]

Hello @smitpatel!

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[ghost]

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