Fix invalid package names missed in previous commit

While renaming `org.oacsd` to `org.oac`, some classes were missed to
redefine the package name. This is fixed in this commit along some
import clearings.
Replace `ElecSystemInitialized` fixture

By a common one named `ColdAndDarkSystem`.
Replace deprecated `MustMatchers`

By `Matchers` using verb `should` rather than `must` for matchers.
Add TR devices to the electrical system

Logic for TR1 and TR2 implemented.
Move dev state condition to `ConditionEvaluator`

Rather than repeating again and again the same `StateChangedEvent`
pattern matching.
Add TR1 & TR2 contactors

That open the current flow to the DC BUS 1 & DC BUS 2, respectively.
Add DC BUS 1 & DC BUS 2

And move the TR contactors to the DC system they actually belong to.
Make possible to evaluate multiple conditions

The `ConditionEvaluator` trait only allowed one condition per object
to be watched. This change refactors that code to allow multiple
conditions to be watched by a single device.