Make Atropos initilization more granular

[pavlenko-volodymyr]

Split Atropos between initialization and main action.
Will be helpful in case when Atropos instance is created manually without Moirai.
Also is a starting point for refactoring Atropos's main_loop to the more flexible way of using.

Thanks

[MayureshGharat]

Hi @pavlenko-volodymyr , thanks for the patch. Simoorg can have multiple Atropos each for a fate book that run under a single Morai currently.
Can you explain the use case for :
"Will be helpful in case when Atropos instance is created manually without Moirai."

[pavlenko-volodymyr]

Hi @MayureshGharat,
my use case needs ability to create Atropos instances without using Moirai and separate initialization from main usage.
In general this will be useful for those who plan to use their own implementation of Moirai, for e.g.
using pool of threads/processes/greenlets or use other implementation of REST API or else.

[MayureshGharat]

@sarathsreedharan @suletm would you mind taking a look at this?

[sarathsreedharan]

Hey @pavlenko-volodymyr one point I wanted to raise, was that this would definitely require unit test updates (atleast for atropos tests) could you include that in the pull request