[Heartbeat] Add tag based filtering support when running synthetic monitors

[vigneshshanmugam]

Describe the enhancement:

The synthetics agent already supports both tags based filtering via the --tags tag-a, tag-b and other glob based filtering via --match. We need the same capability like how tags are used in ICMP based monitors and extend it to the synthetic monitors.

- type: browser
  id: browser-inline
  filter_journeys: 
    tags: ["home", "app"]
    match: "foo"
  name: browser-inline
  schedule: "@every 1m"

These applied tags would then be mapped under each monitor on the Kibana Uptime UI.

[elasticmachine]

Pinging @elastic/uptime (Team:Uptime)

[paulb-elastic]

@vigneshshanmugam does anything else need doing here?

If I add a tag for a browser test with tags: ["testTag1", "testTag2"] for example, I do see these in Uptime:

[vigneshshanmugam]

@paulb-elastic We need to make sure these tags are sent to the Synthetics CLI to make use of the filtering logic which is essential for big projects like Kibana. We need to enable this - elastic/synthetics#300

[vigneshshanmugam]

@paulb-elastic I see the confusion, After discussion with Andrew, I have updated the description and moved the tags under filter_journey option.

[dominiqueclarke]

Works as expected with both tags and match. Tested against beats 7.15 branch with synthetics 1.0.0-beta.12