[BUG] Missing error handling at PresetReaction

[AronNovak]

What steps does it take to reproduce the issue?

Define a context reaction with non-existing action ID and perform the given action.

• When does this issue occur?

When the code in PresetReaction tries to invoke the action.

• Which page does it occur on?

Upon custom integration of Islandora, with custom configuration.

• What happens?
  PHP fatal error due to the failure of loading the action.

• To whom does it occur (anonymous visitor, editor, administrator)?

Role-agnostic issue.

• What did you expect to happen?

A Drupal database log entry should be created about the problem.

Which version of Islandora are you using?
2.11.0

Any related open or closed issues to this bug report?

Screenshots: