Length-Free Conversion

Describe the solution you'd like

For conversions of the form to_xxx and resize in IEEE packages (std_logic_1164, numeric_std, numeric_std_unsigned, numeric_bit, numeric_bit_unsigned, fixed_generic_pkg, float_generic_pkg, math_real, math_complex) that currently require size and/or range information, extract that information using function return identifiers to retrieve the range information.

Describe alternatives you've considered

Do nothing.

Additional context

Some aspects already done by #244 packages!6

Ownership of this issue

Everyone owns this. Please edit.