Make hint window persistent across restarts

The current hint system stores a window of hints as defined by max_hint_window_in_ms, however this window is not persistent across restarts.

Examples (cluster with RF=3 and 3 nodes, A, B, and C):

1. A goes down
2. X ms of hints are stored for A on B and C
3. A is restarted
4. A goes down again without hints replaying from B and C
5. B and C will store up to another max_hint_window_in_ms of hints for A

1. A goes down
2. X ms of hints are stored for A on B and C
3. B is restarted
4. B will store up to another max_hint_window_in_ms of hints for A

Note that in both these scenarios they can continue forever. If A or B keeps getting restarted hints will continue to pile up.

Idea of this ticket is to stop this behaviour from happening and only ever store up to max_hint_window_in_ms of hints for a particular node.