Bug 17425: Make Koha::Object raise exceptions

Bug 17425: Make Koha::Object raise exceptions

This patch makes Koha::Object raise exceptions in the following
situations:
- When a non existent accessor is called
- When a non existent property is tried to be updated using ->set

On implementing this change, we introduce Koha::Exceptions::Object class
to contain all Koha::Object-specific exception definitions.

Unit tests for this change are introduced in
t/db_dependent/Koha/Objects.t

To test:
- Apply the patches on master
- Run:
  $ prove t/db_dependent/Koha/Objects.t
=> SUCCESS: Tests return green
- Sign off

Note: A followup introduces the dependency for Try::Tiny. It needs to be
present for running the tests.

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>