refactor: copy search symbols to search types
requested to merge rvt/refactor-search-types-copy-symbols-types into rvt/refactor-search-types-propagate-commit-parameters
Created by: rvantonder
Stacked on #7495.
This just expands the protocol.SearchArgs type to its full struct definition (it is copied directly from SearchArgs in symbols/protocol/symbols.go. From here we can see what state is being duplicated or otherwise exclusive to symbols search in types.go.
This is needed for follow up diffs that will separate logic for indexed search and PatternInfo state.