feat(frontends/lean): annotate 'notation' subterms with 'noinfo' annotation (goal: improve typeinfo generation); fix initialization problem (with annotations)

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
fix(frontends/lean/elaborator): uninit variable

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(frontends/lean/server): use separate thread for processing requests in server mode, interrupt whole parser when on interruption (when collecting information)

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
chore(doc/server): update server mode documentation

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
fix(frontends/lean/inductive_cmd): generate index for inductive decls, introduction rules, and recursor/eliminator

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
refactor(frontends/lean/info_manager): add method info_data::compare

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>