feat(kernel/environment): add method for adding declarations that were not type checked (if trust_lvl() > LEAN_BELIEVER_TRUST_LEVEL)

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(library/kernel_bindings): expose environment::add(declaration) method in the Lua API, and add example to demonstrate its usage

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
refactor(library/kernel_bindings): rename empty_environment ==> bare_environment in the Lua API

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(kernel): add mk_hott_environment function for creating HoTT compatible environments

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(library/kernel_bindings): add hott_environment Lua API

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
feat(library/module): add declaration reader

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