Pass named functions arguments in correct order and with default values

[shanginn]

What was changed

Allow for named arguments in workflow handler, signals and activities params

Why?

Because it's possible in PHP

Checklist

1. Closes Issue 282

2. Tested in NamedArgumentsTestCase

[roxblnfk]

Hello. Thank you for your contribution to the Temporal PHP SDK.
I've done an initial review and made some edits. However, there's still a lot of work to be done. Please note that there is an opportunity to create different stubs (like ChildWorkflow) through the Workflow:: facade. We need to ensure that named arguments also work in such a flow.

[roxblnfk]

Need to fix arguments sorter. See the new unit tests

[roxblnfk]

LGTM
@shanginn need to fix psalm issues

[wolfy-j]

LGTM