What happened?

gr_modtool makeyaml produces some invalid fields due to the regex parsing of the impl files

System Information

OS: Ubuntu 20.10
GR Installation Method: source

GNU Radio Version

3.10-git (master)

Specific Version

395-gc3c411be

Steps to Reproduce the Problem

1. Create a block with gr_modtool
2. gr_modtool makeyaml myblock

The output yaml has a few issues - see log output

Relevant log output

id: cudademo_multiply_const
label: multiply const
category: '[Cudademo]'
templates:
  imports: import cudademo
  make: cudademo.multiply_const(${k})
parameters:
- id: k
  label: K
  dtype: float
inputs:
- label: in
  domain: stream
  dtype: raw
  multiplicity: 1 /* max inputs */
outputs:
- label: out
  domain: stream
  dtype: raw
  multiplicity: 1 /*max outputs */
file_format: 1