Verification Statements do not support Printable

**Type of issue**: feature request

**Impact**: API addition (no impact on existing code)

Currently the Verification Statements (i.e. `assert` and `assume`) can take additional arguments that will result in a message being printed when the condition is violated. However, it only supports the "C"-style printing, i.e.: `assert(a, "a=%d", a)`. In addition it would be nice if it also supported the Scala/Python style of printing like `printf` already does, i.e. `assert(a, p"a=$a")`.

Start with the implementations or entry points for the assert and assume verification statements, then compare their message handling with printf's existing Printable support. Done means both statements accept Scala/Python-style Printable expressions such as p"a=$a" while preserving the existing C-style arguments.

Written by the indexing model from the issue text.