Fix (pillar|grains).filter_by with salt-ssh

[lkubb]

What does this PR do?

• Adds pillar.filter_by to the salt-ssh wrapper, which makes it work as expected while using salt-ssh (see linked issue)
• Adds some tests for grains.filter_by salt-ssh wrapper (tried but failed to reproduce grains.filter_by does not use default parameter when using salt-ssh #46948 / Nested grains.filter_by calls fail when using salt-ssh #50247)
• Syncs grains.filter_by salt-ssh wrapper with the current execution module function, which makes use of the utility module. This might fix the above issues, if they are still relevant.

What issues does this PR fix or reference?

Fixes: #56093

Previous Behavior

• pillar.filter_by always defaults to the default key using salt-ssh
• grains.filter_by does not support nested grains and does not deepcopy the merging dict

New Behavior

• pillar.filter_by works as usual
• grains.filter_by works as usual

Merge requirements satisfied?

• Docs
• Changelog - https://docs.saltproject.io/en/master/topics/development/changelog.html
• Tests written/updated

Commits signed with GPG?

Yes

[cmcmarrow]

THX for the PR