<location> support for asciidoctor and sass targets

[grisumbras]

Proposed changes

<location> is removed from property sets for SASS and ASCIIDOC targets. This makes them behave differently from other targets, and prevents users to put them into a specific place. Normally it can be circumvented using an install rule, but when multiple files are created it becomes less trivial. The change fixes the issue by whitelisting <location> feature for those types.

Types of changes

• Bugfix (non-breaking change which fixes an issue)

Checklist

• I searched the discussions
• I searched the closed and open issues
• I read the contribution guidelines
• I added myself to the copyright attributions for significant changes
• I checked that tests pass locally with my changes
• I added tests that prove my fix is effective or that my feature works
• I added necessary documentation (if appropriate)