Evaluate usage of `[[:blank:]]` instead of `\s` across the project's regexes

#### Description of problem:
`\s` covers all whitespace characters including newlines and in somecases newlines are not expected, for example:

https://github.com/ComplianceAsCode/content/blob/1880981b573f38f334d74765c54676af24f15a25/shared/templates/sysctl/oval.template#L20

would match something like:

```
{{{ SYSCTLVAR }}}
=1
```

and that's not really desired