⚡ Replaced pager with infinite loop (using react-virtualize)

[ole1986]

WARNING: This is a very early PR and need more attention before merging

This PR contain the following changes:

• Replaced pager with react-virtualized incl. AutoSizer and InfiteLoop while using List (source example)
• Rewritten BranchGraph to make compatible with InfiniteLoop (@DonJayamanne I am no expert in this, so feel free to double check)
• Future support for repository state change events being passed to browser app (registered through ResultActions.onStateChanged) - see browser/src/containers/App/index.tsx (not yet in use)

Known issues

• BranchGraph does not seem to correctly parse merges from other branches when using "all branches"
• Search has not fully tested after changing to react-virtualized
• BranchGraph does not meet all previous changes (E.g. rounded corners)
• Repository State event is triggered to often (due to git commands being called through exec) to use it properly
• Graph is not correctly positioned when scrolling per pixel
• File History is showing branch graph (which should be disabled)

InfiniteLoop in action

[DonJayamanne]

Will check this weekend, apologies for the delay