feat: add preventScrollToFocusedMonth prop

[mdelez]

Types of changes

What types of changes does your code introduce?

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• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Description

I find it distracting that the calendar jumps when you have more than 1 month at a time displayed. This prop disables the shifting of the focused month to the left side.

[goguda]

Good idea, it's something we noticed while migrating the original codebase to TS. Merged, thank you!