[ExportVerilog] Add ModportType support for non-extern hw.module ports

[dmlockhart]

Add support for !sv.modport<> typed ports on non-extern hw.module:

• printPackedTypeImpl: emit InterfaceName.ModportName for ModportType.
• Port direction: suppress input/output/inout keywords for modport ports.
• Wire keyword: suppress wire keyword for modport ports.

Modport-typed ports (e.g., MyBundle.sink) already encode their direction in the interface modport definition, so the direction and wire keywords are suppressed when emitting these ports.

This enables using SystemVerilog interface modports as port types on regular (non-extern) modules, producing correct Verilog output like:

module MixedPorts(
  input  [31:0]        data_in,
  MyBundle.sink        intf_port,
  output [31:0]        data_out
);

[uenoku]

Generally looks good to me. Thank you for sending a PR! !sv.modport hasn't been used much so it may not have good coverage. Please feel free to open an issue if you encounter any problems.

Strictly speaking I think it's necessary to add more complicated logic around // Determine the width of the widest type we have to print so everything lines up nicely. to compute the accurate number of whitespace padding, i.e:

Current output (startOfNamePos=len("output") + len("MyBundle.sink") + 1):

input  [31:0]        data_in,
MyBundle.sink        intf_port,
output [31:0]        data_out

Ideal Output (startOfNamePos=max(len("output"), len("MyBundle.sink")) + 1):

input  [31:0] data_in,
MyBundle.sink intf_port,
output [31:0] data_out,

However currently the logic is a bit hardcoded around the assumption that ports are only input or output so I'm fine with merging this as is for now and cleaning up the hardcoded assumptions in a follow-up.

[uenoku]

Please remove dirWidth and totalWidth.

Suggested change

	ps.nbsp(totalWidth - portTypeStrings[portIdx].size());
	ps << portTypeStrings[portIdx];
	if (portTypeStrings[portIdx].size() < startOfNamePos)
	ps.nbsp(startOfNamePos - portTypeStrings[portIdx].size());

[uenoku]

Please format and remove redundant variables, otherwise LGTM!