Added 'multiple' operator to allow complex criteria matching on payload items

[erceth]

The new "multiple" operator is similar to "search" except it adds some additional features. It allows multiple evaluations of the same payload item by a rule. This solves a problem brought up in #2656

Now evaluations such as the following are possible:

trigger.body.location.latitude:
  type: multiple
  condition: all2any
  pattern:
    item.value:
      type: "lessthan"
      pattern: 40
    item.value#2:
      type: "greaterthan"
      pattern: 50
trigger.body.location.longitude:
  type: multiple
  condition: all2any
  pattern:
    item.value:
      type: "greaterthan"
      pattern: -90
    item.value#2:
      type: "lessthan"
      pattern: -100

In this example the action for this criteria would occur when the latitude and longitude payload data falls outside the area specified, creating a simple box geo-fence.

There are four different criteria conditions:

• all2all - true if all payload items match all criteria items
• all2any - true if all payload items match any criteria items
• any2any - true if any payload items match any criteria items
• any2all - true if any payload items match all criteria items

When specifying payload data in the rule, the "#" symbol and text after it are ignored. This allows dictionary keys to be unique but refer to the same field. Any text can go after the hash.

Using the four different criteria conditions, inclusive or exclusive ranges for the same field are possible.

See tests for more examples.

The multiple operator could eventually replace the search operator.

Closes #2656

[erceth]

@armab, @nzlosh ,@cognifloyd
I was wondering if you had a chance to look at this pull request yet. I'm a first time contributor. Is there anything else I need to do to get it ready for review?

[erceth]

@armab , @nzlosh , @cognifloyd
I was wondering if you had a chance to look at this. Is this even a change that is wanted? I would like some feedback.

[arm4b]

Thanks for the contribution! 👍
This looks like an interesting feature cc @m4dcoder.

Added a couple of comments and questions.

[cognifloyd]

This will make the search operator much more useable. Thanks!

The multiple name is my only hangup with this. I like the idea of adding this functionality to search as it will make it much more useful and useable.
Thanks!

Also, I'll edit the PR description to add closes annotations.

[arm4b]

Thanks for the changes!

Left a couple more comments.
Think about this PR just as adding 2 new criteria.

Please prepare the corresponding documentation for the new criteria in the https://docs.stackstorm.com/rules.html#advanced-comparison so we could merge everything in one go.
Additionally, we'll need a changelog for this PR: https://github.com/StackStorm/st2/blob/master/CHANGELOG.rst

[erceth]

I believe I have made all the changes asked of me. Here is a link to the documentation pull request. StackStorm/st2docs#1106

[cognifloyd]

Oh wow. That's a lot simpler. That really helps me to see the diff with search.
Looks fantastic!

[arm4b]

Thanks, everyone! 👍

Just waiting for st2docs final adjustments to merge this.

[erceth]

Docs updated