feat: Implement preimage for ceil and round functions

[kumarlokesh]

Which issue does this PR close?

• Closes Implement preimage for ceil and round functions #20197.

Rationale for this change

floor(col) = N is already rewritten via ScalarUDFImpl::preimage so that
predicates push into Parquet row-group statistics. ceil and round admit
the same rewrite but have boundary conventions that don't fit the API's
half-open [lower, upper) form: ceil(x) = N is (N-1, N], and round(x) = N
is sign-dependent under half-away-from-zero. Both can be expressed in
[lower, upper) form by shifting closed boundaries with f::next_up()

What changes are included in this PR?

• CeilFunc::preimage - Float32/Float64 and all four Decimal variants.
• RoundFunc::preimage - Float32/Float64 (with optional literal dp) and all
  four Decimal variants for dp = 0.
• Helper functions ceil_preimage_float / ceil_preimage_decimal in ceil.rs,
  round_preimage_float / round_preimage_decimal in round.rs.
• A small FloatExt trait in each file bridging num_traits::Float to
  f32::next_up() / f64::next_up().

No changes to the preimage API, the simplifier, or any optimizer rule.

Are these changes tested?

Yes.

• Unit tests cover positive / negative / zero / non-integer / null / overflow /
  non-finite cases for both float and decimal variants.
• SLT tests (ceil_preimage.slt, round_preimage.slt) cover data correctness
  and EXPLAIN output for all six comparison operators plus
  IS (NOT) DISTINCT FROM and IN/NOT IN.

Are there any user-facing changes?

No public API change. The optimization is transparent and predicate semantics
are preserved exactly.