Parse atmos.yaml CLI config when executing atmos vendor command. Improve OPA policy evaluation and error handling

[aknysh]

what

• Parse atmos.yaml CLI config when executing atmos vendor command
• Improve OPA policy evaluation and error handling

why

• When executing atmos vendor pull command, we need to parse atmos.yaml and calculate the paths to stacks and components folders to write the vendored files into the correct component folder
• Add timeout to OPA policy evaluation (it will show a descriptive error message instead of hanging forever if Rego policy is not correctly defined/formatted or Regex in Rego is not correct)
• Output error in the case when using Regex in Rego policy and the Regex contains a non-escaped backslash

If a regex pattern in the `re_match` function contains a backslash to escape special chars (e.g. `\.` or `\-`),
it must be escaped with another backslash when represented as a regular Go string (`\\.`, `\\-`).
The reason is that backslash is also used to escape special characters in Go strings like newline (\n).
If you want to match the backslash character itself, you'll need four slashes.

[nitrocode]

If v3.1.0 is not an issue, then this lgtm