[Nice To Have] Be able to use a counter inside and outside a sequence

[fbeltrao]

Please provide us with the following information:

This issue is for a: (mark with an x)

- [ ] bug report -> please search issues before submitting
- [x] feature request
- [ ] documentation issue or request
- [ ] regression (a behavior that used to work and stopped in a new release)

Minimal steps to reproduce

Define the following variables:
counter_1, counter_2, counter_3: counters
seq1: [ counter_1, counter_2, counter_3 ]
seq2: [ counter_2, counter_1 ]

Define the template:
{ v1: seq_1, v2: seq_2, v3: counter_3 }

The value of v3 will be "$.counter_3" as we don't support using a counter inside and outside a sequence.

Expected/desired behavior

Same variable can be used inside and outside a sequence.

[gukoff]

Maybe revert Counter behavior, and create a new variable type like ResettingCounter that resets when not used on the iteration?