feat: use exponential backoff algorithm when polling actions (#524)

##### SUMMARY

Replace the constant poll interval of 1 second, with a truncated
exponential back off algorithm with jitter.

Below is a suite of poll interval (in seconds) generated by the new
algorithm:
```
1.49
2.14
5.46
6.51
6.57
5.57
5.98
7.13
6.59
7.10
5.54
5.03
6.56
5.96
6.72
7.21
7.05
5.31
5.60
6.33
6.82
5.42
6.08
6.60
TOTAL: 140.77
```

changelogs/fragments/exponential-actions-polling-interval.yml

@@ -0,0 +1,2 @@
+minor_changes:
+  - Use a truncated exponential backoff algorithm when polling actions from the API.