Event Details for notification emails

[kbrock]

Part of ManageIQ/manageiq#17673

This allows extra details to be part of notification emails

[miq-bot]

Checked commit kbrock@d59288f with ruby 2.3.3, rubocop 0.52.1, haml-lint 0.20.0, and yamllint 1.10.0
2 files checked, 1 offense detected

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• 💣 💥 🔥 🚒 - Linter/Haml - Linter::Haml STDERR:

warning: parser/current is loading parser/ruby23, which recognizes
warning: 2.3.6-compliant syntax, but you are running 2.3.3.
warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.

[mzazrivec]

@kbrock Please remove the pending core label once the core PR is merged. Thanks!

[kbrock]

@mzazrivec Since the hash will not include this key, this will be a no-op before core is merged.

Can we merge this here before there?