7.5.x compatibility

[mejarrett]

This PR needs to be put against a new branch (7.5-dev?), or it will break the 7-dev branch for Kibana 7.1 through 7.4.

Differences in this PR compared to previous versions of plugin:

Updates for Kibana 7.5 compatibility:

• Switched from abandoned vis library to vis-network library (my change for this was also merged in the 7-dev plugin branch)
• Updated Kibana visualization imports due to massive directory structure changes, as well as registration of the visTypes registry
• Had to import Kibana’s AggConfig to get to aggregation data
• Set the edge size ID after all others, since the needed column depends on which other buckets are being used

Color Node

• Can now be used with just primary nodes (single-node type graph)
• Color node legend is moved a little closer to center, which is helpful when smaller result sets are returned. It may appear within the results of large result sets. Still a static placement however.

Personal preference changes:

• Removed the Top Values node and edge size, and corresponding maxCutMetricSizeNode and maxCutMetricSizeEdge variables. Since these contain a default value of 5000, comparing 5000 to each returned node/edge value will always cause data flattening whether Math.min or Math.max is used (as long as you have data that is smaller or larger than the default). I think this option could be added back to the plugin in the future, as long as no default value is used - it would only need to be used if explicitly set by the user.

Pop-up labels / tooltips (work by @craig-cogdill):

• Are turned on by default
• Now show edge sizes, if set, with the metric + data (ex. Average bytes: 1234) - not implemented for node-relation
• Primary nodes show the field + result (ex. Ip: 127.0.0.1), as well as the metric + data (ex. Average bytes: 1234)
• Now seconday nodes, if used, show the field + result (ex. DestIp: 1.2.3.4)

UI changes to the plugin:

• Updated the plugin icon to match the other Kibana light-mode icons
• Updated the default primary and secondary node colors to match colors used by Kibana
• Updated the “options” tab html so the secondary node options appear
• Updated wording and spacing within the “options” tab
• Loading message is closer to Kibana style
• No changes were made to make the plugin adhere to Kibana’s dark mode unfortunately

“Bugs”

• When creating a new network visualization, there’s immediately a displayed error stating that plugin must be node-node or node-relation (previously only appeared when choosing an incorrect setup, like node-node-relation) - this can be easily fixed, but I didn’t prioritize it
• Using “dynamic” as the “Smooth type” seems to cause edges to be drawn multiple times in some cases

[fpompermaier]

I can confirm that it works on my Kibana 7.5

[dlumbrer]

Thanks for the awesome work!