Cardano Updates

## Description
First set of changes to make use of out-of-the-box pool_stat table
instead of relying on grest.pool_active_stake_cache.
Once these are reviewed and tested we can have a go at disabling the
logic associated with that cache population and anything that depends on
it (e.g. currently it is responsible for keeping a control_table record
updated that at least one other cron job/cache depends on)



## Which issue it fixes?
<!--- Link to issue: Closes #issue-number -->

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Co-authored-by: hodlonaut <[email protected]>
Co-authored-by: Dostrelith <[email protected]>

## Description
<!--- Describe your changes -->
- calculate all dangling delegations in CTE
- join some CTEs into one
- add temp memory increase for this query

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Co-authored-by: RdLrT <[email protected]>

Reduced work_mem setting from 4GB to 512MB for query optimization.