Add ability to set up horizontal spacing for block style

[dimkanovikov]

Description

Added ability to set up horizontal spacing (left and right) for text blocks in a flexible way (instead of using indents).

Related Issues

I have not found opened issues related to this feature, but it was my need to format blocks differently on the screen because of my use case (screenplay writing application).

Type of Change

• ✨ New feature: Adds new functionality without breaking existing features.
• 🛠️ Bug fix: Resolves an issue without altering current behavior.
• 🧹 Code refactor: Code restructuring that does not affect behavior.
• ❌ Breaking change: Alters existing functionality and requires updates.
• 🧪 Tests: Adds new tests or modifies existing tests.
• 📝 Documentation: Updates or additions to documentation.
• 🗑️ Chore: Routine tasks, or maintenance.
• ✅ Build configuration change: Changes to build or deploy processes.