[Lens] Implement counter rate expression

[mbondyra]

Summary

Fixes #46627

Adds lens_counter_rate function.

The counter rate function works almost exactly like derivative expression – if value is increasing or equal, it returns the difference between current and previous value. If value decreased compared to the previous value, the function outputs the current value. Here's the example:

input	output	comment
1	undefined	previous value doesn't exist
5	4	increasing dif(5-1)
11	6	increasing dif(11-6)
4	4	decreasing diff, so the counter is reset to the value
4	0	dif(4-4)

Special cases

For undefined:

input	output	comment
1	undefined	previous value doesn't exist
5	4	increasing dif(5-1)
undefined	undefined	undefined current value
3	undefined	undefined previous value

Question: NaN case

Should value after NaN be also NaN (eg. counter between NaN and 2 - that's that derivative do) or should it be NaN?

input	output	comment
1	undefined	previous value doesn't exist
3	2	increasing dif(3-1)
{} (converted to NaN)	NaN
2	2 or NaN??	**This is the doubt**
3	1	increasing diff (3-2)

The expression takes inputColumnId, outputColumnId, outputColumnName, by (similar behavior to new expression time series functions)

Checklist

• Any text added follows EUI's writing guidelines, uses sentence case text and includes i18n support
• Unit or functional tests were updated or added to match the most common scenarios

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)

[mbondyra]

@elasticmachine merge upstream

[kibanamachine]

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@elasticmachine merge upstream