[C++] Implement casts between date32 and date64

[asfimport]

Reporter: Wes McKinney / @wesm
Assignee: Wes McKinney / @wesm

Related issues:

• [C++] Type casting function kernel suite (Is contained by)

_{Note: This issue was originally created as ARROW-1482. Please see the migration documentation for further details.}

[asfimport]

Wes McKinney / @wesm:
Resolved in 54d5c81