Changelog 4.5.1 (osquery#6692)

Changelog for 4.5.1

Add 4.5.0 CHANGELOG (osquery#6646)

Add additional changelog items (osquery#6523)

Additional changelog items

Add CMake module for system icu library

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>

release: updating changelog for 4.3.0 release (osquery#6387)

regex engine replacement: boost -> std (osquery#6236)

Replace regex engine with std

Fixes issue osquery#6061

Co-authored-by: scoders <sahil@cs.toronto.edu>

changelog: Add CHANGELOG for 4.1.2 (osquery#6130)

CMake: Prefer Python 3.7 then 3.6 (osquery#6057)

We are not currently ready for Python 3.8,
so we prefer either the newest 3.7 or 3.6.

Add New_Release GitHub issue template (osquery#5979)