Incorrectly parse the error/warning information of iverilog when linting.

[simon-zh-1234]

Describe the bug
The extension cannot parse the output information of iverilog correctly, say, it does not know how to determine the location of colon.
For example, I have two files float_add.v and test.v, in the former one two module float_add and test are defined and in the later one test are defined again by mistake. And in test.v I include float_add.v.
If I run iverilog test.v -t null, the output is
test.v:46: Module test was already declared here: ./float_add.v:69
However, if I save test.v in editor, the linting information is only
./float_add.v
Obviously here colon is incorrectly parsed.

Environment:

• OS: Ubuntu 20.04 with Linux 5.8.0-63-generic.
• VS Code version [1.58.2]
• Extension version [1.5.0]
• lint tool is iverilog

Steps to reproduce
Steps to reproduce the behavior:

1. Create two file float_add.v and test.v
2. write two module float_add and test in float_add.v
3. include float_add.v in test.v and write a module test in test.v
4. Save float_add.v and test.v, compare the linting information in test.v and the output of iverilog test.v -t null