Add --target_timeout flag for qemu_user template command

[kananb]

Summary of the Pull Request

Adds the --target_timeout flag to the onefuzz template libfuzzer qemu_user command.

What is this about?

PR Checklist

• Applies to work item: #xxx
• CLA signed. If not, go over here and sign the CLI.
• Tests added/passed
• Requires documentation to be updated
• I've discussed this with core contributors already. If not checked, I'm ready to accept this work might be rejected in favor of a different grand plan. Issue number where discussion took place: #xxx

Info on Pull Request

What does this include?

Validation Steps Performed

How does someone test & validate?

[codecov-commenter]

Codecov Report

Merging #3277 (b98add8) into main (15351a7) will increase coverage by 0.33%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #3277      +/-   ##
==========================================
+ Coverage   29.61%   29.95%   +0.33%     
==========================================
  Files         332      301      -31     
  Lines       38890    33669    -5221     
==========================================
- Hits        11516    10084    -1432     
+ Misses      27374    23585    -3789     

see 106 files with indirect coverage changes