arrow

GH-40183: [C++] Fix cast function bind failed after add an alias name through AddAlias (#40200)



### Rationale for this change

Cast function bind failed after add a alias name through AddAlias.

### What changes are included in this PR?

Add a const `cast_function` which registered in `AddFunction` for check cast alias in `arrow::compute::GetFunction`.

### Are these changes tested?
Yes

### Are there any user-facing changes?
Yes, cast's alias name can also execute with expression system.

* GitHub Issue: #40183

Authored-by: hugo.zhang <hugo.zhang@openpie.com>
Signed-off-by: Benjamin Kietzman <bengilgit@gmail.com>