* validator/client: process Sync Committee roles separately
In a DV context, to be compatible with the proposed selection endpoint, the VC must push all partial selections to it instead of just one.
Process sync committee role separately within the RolesAt method, so that partial selections can be pushed to the DV client appropriately, if configured.
* testing/util: re-add erroneously deleted state_test.go
* validator/client: fix tests
* validator/client: always process sync committee validator
Process sync committee duty at slot boundary as well.
* don't fail if validator is marked as sync committee but it is not in the list
ignore the duty and continue
* address code review comments
* fix build
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Co-authored-by: Radosław Kapka <rkapka@wp.pl>