feat: extend single ndv optimization to non-arithmetic supporting types for equality predicates (#21473)

## Which issue does this PR close?
- Closes #21109.

## Rationale for this change
In the case of equality we can say ndv is 1 for non-numeric types as
well. Please check issue for detailed explanation

## What changes are included in this PR?
Adding a type-agnostic pattern-matching layer that inspects the
predicate tree for col = literal shapes and sets NDV=Exact(1) regardless
of column type

## Are these changes tested?
Yes existing and additional unit tests.

## Are there any user-facing changes?
No

Author: buraksenn