feat: add safe write functionality

[dpakpak]

Issue #, if available:

Description of changes: Added functionality to write safely to files. The history file would sometimes have a partial write leaving the history file created but empty, causing ec2-macos-init to not be able to parse the history file.

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[dpakpak]

Only the 1st, 2nd, and Last commits are important. The other commits were all reverted.

[dpakpak]

Resolved merge conflicts in instancehistory.go

[jahkeup]

@dpakpak @mattcataws before we merge this, let's meet up and squash the commits into a tidy set of commits 👍🏽