Added a way to use psr-3 messages.

[Daniel-KM]

Allows to use psr-3 compliant messages : https://www.php-fig.org/psr/psr-3

When accepted, another pr will allow to use psr strings in logs.

Fixes #1183

[zerocrates]

What kinds of situations are you envisioning where you might use this new message class outside the messenger or the logger? I'd really prefer to see it use the same code path as is currently used in the messenger for translating the sprintf-based messages... in other words I'd be happier with something that altered the existing Message and created an interface the two message types would share (something like getMessage() and interpolate() or whatever it would be called), and altered our translator to check for that interface rather than Message.

[Daniel-KM]

The main usage is messenger and logger. I don't have any other usage currently.

[Daniel-KM]

In fact, there is another usage: to write e-mails (config form of module GuestUser), where string placeholders are simpler to use by end users.

[Daniel-KM]

Rebased on 1.4.

[Daniel-KM]

Rebased on 2.0.

[Daniel-KM]

Merged for laminas.

[Daniel-KM]

Merged with upstream/develop.