fix(frontends/lean/decl_cmds): typo

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
refactor(frontends/lean): minor code reorg

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
refactor(frontends/lean): use expr_struct_set when collecting locals

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
refactor(frontends/lean/builtin_cmds): cleanup 'check' command

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
fix(frontends/lean): bug in section management

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
refactor(frontends/lean): eliminate the abstract method 'family' from parser

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
fix(frontends/lean): more bugs in section management

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