Merge #7917: Optimize reindex
b4d24e1 Report reindexing progress in GUI (Pieter Wuille)
d3d7547 Add -reindex-chainstate that does not rebuild block index (Pieter Wuille)
fb8fad1 Optimize ActivateBestChain for long chains (Pieter Wuille)
316623f Switch reindexing to AcceptBlock in-loop and ActivateBestChain afterwards (Pieter Wuille)
d253ec4 Make ProcessNewBlock dbp const and update comment (Pieter Wuille)