Add `ChainPorter` pre-broadcast validation for pre-anchored sends#1875

ffranr wants to merge 3 commits intomainlightninglabs/taproot-assets:mainfrom

wip/add-chainporter-prebroadcast-validation-statelightninglabs/taproot-assets:wip/add-chainporter-prebroadcast-validation-stateCopy head branch name to clipboard