…1365)

This pull request updates the Ruby CLI to show the compiled source when
the `compile` subcommand produced invalid Ruby

**Before**
```
❯ bin/herb compile test.html.erb
Compiled template produced invalid Ruby:
  - unexpected end-of-input, assuming it is closing the parent top level context (line 4)
  - expected a matching `)` (line 5)
  - unexpected end-of-input; expected a `)` to close the arguments (line 4)
``` 

**After**
```
❯ bin/herb compile test.html.erb
__herb = ::Herb::Engine; _buf = ::String.new; _buf << __herb.h((render Foo.new do; _buf << 'hello'.freeze; end # comment))
 _buf << '
'.freeze;
_buf.to_s

Compiled template produced invalid Ruby:
  - unexpected end-of-input, assuming it is closing the parent top level context (line 4)
  - expected a matching `)` (line 5)
  - unexpected end-of-input; expected a `)` to close the arguments (line 4)
``` 

Inspired while working on #1363