Refactor and improve DB size generator

[rubo]

Changes

• Fixed the DB size generator to update the docs for the latest released version along with the next version
• Refactored command line arguments handling
• Refactored file handling to avoid back-and-forth with copying of the docs files. No need to copy doc files that should be modified. Now it knows where to look and what to do.
• Removed "v" from version strings

Types of changes

What types of changes does your code introduce?

• Bugfix (a non-breaking change that fixes an issue)
• New feature (a non-breaking change that adds functionality)
• Breaking change (a change that causes existing functionality not to work as expected)
• Optimization
• Refactoring
• Documentation update
• Build-related changes
• Other: Docs generator refactoring

Testing

Requires testing

• Yes
• No

Notes on testing

Tested manually.