fix: logger initialization before flags parsing

[DmitriyLewen]

Description

We need to init logger before flags parsing to avoid wrong log messages format.

before:

➜  trivy -d image alpine -c config.yaml --vuln-type os 
2024/08/22 14:09:16 WARN '--vuln-type' is deprecated. Use '--pkg-types' instead.
2024/08/22 14:09:16 INFO Loaded file_path=config.yaml
2024-08-22T14:09:16+06:00       DEBUG   Parsed severities       severities=[UNKNOWN LOW MEDIUM HIGH CRITICAL]
...

➜ trivy -q image alpine -c config.yaml --vuln-type os  
2024/08/22 16:22:17 WARN '--vuln-type' is deprecated. Use '--pkg-types' instead.
2024/08/22 16:22:17 INFO Loaded file_path=config.yaml

alpine (alpine 3.20.2)

Total: 0 (UNKNOWN: 0, LOW: 0, MEDIUM: 0, HIGH: 0, CRITICAL: 0)

after

➜  trivy -d image alpine -c config.yaml --vuln-type os
2024-08-22T14:08:58+06:00       WARN    '--vuln-type' is deprecated. Use '--pkg-types' instead.
2024-08-22T14:08:58+06:00       INFO    Loaded  file_path="config.yaml"
2024-08-22T14:08:58+06:00       DEBUG   Parsed severities       severities=[UNKNOWN LOW MEDIUM HIGH CRITICAL]
...

➜ trivy -q image alpine -c config.yaml --vuln-type os

alpine (alpine 3.20.2)

Total: 0 (UNKNOWN: 0, LOW: 0, MEDIUM: 0, HIGH: 0, CRITICAL: 0)

Related issues

• Close #7124

Checklist

• [x] I've read the guidelines for contributing to this repository.
• [x] I've followed the conventions in the PR title.
• [ ] I've added tests that prove my fix is effective or that my feature works.
• [ ] I've updated the documentation with the relevant information (if needed).
• [ ] I've added usage information (if the PR introduces new options)
• [x] I've included a "before" and "after" example to the description (if the PR is a user interface change).