Improve flow and HA-flow history response structure and API

[dmitrii-beliakov]

This feature is intended to improve flow and HA-flow history responses, so that the information is more clear, structured, easier to understand. This feature will introduce new API and will not break any existing API.

1. Response payload structure
   A payload of the history response will have the following structure:

[collection of history events]
   |- History event
        | - history event body fields
        | - [collection of actions]
              | - action body fields
              | - dump
                   | - dump fields

Each action could have one dump. When it is required to have more dumps (such as dump before and dump after), the dumps are saved in separate actions. This feature will resolve a problem of having two dumps inside one event when dumps are saved for primary paths and then for the protected paths.

2. Response payload fields
   Name timestamp fields to clearly distinguish event's timestamp from history record timestamp. Format timestamps into human-readable format (ISO 8601).
3. Allow request parameters for filtering to accept timestamps in ISO 8601 format as well as epoch time in seconds and milliseconds. (change filter parameter type from long to string)
4. Rename task ID to correlation ID.

[dmitrii-beliakov]

This issue will help to resolve other related issues. For example, mentioned in comments in #5497 issue related to saving paths in the IN_PROGRESS state. Once the dumps are linked to the actions is will be more clear why they are in this state, as well as it will be easier to investigate and fix issues, because it will be easier to localize them.

https://github.com/search?q=repo%3Atelstra%2Fopen-kilda%20BaseFlowResourceAllocationAction&type=code