Moving the multiple overriden execTransaction calls to the end is more readable.
The other write operations are also now grouped together.

This also move the OwnerSimulator into the lib, which nicely abstracts that away.

Also make lib functions internal which removes the deploy and linking with solidity libs.

It was only used once.

This refactor removes a few different variable which were unnecessary
and added to the confusion.

This commit introduces the ability to remove multiple owners at once in the LivenessModule.sol contract. A new function removeOwners has been added, which accepts arrays of previous owners and owners to be removed. The existing removeOwner function has been updated to use a new internal function _removeOwner. The _getPrevOwner function has been removed as it is no longer needed.

Co-authored-by: Matt Solomon <matt@mattsolomon.dev>

Standardizing on the term owner rather than signer except in and around calls to _getNSigners.

There was a bug in the remove all owners flow that would leave two owners on the safe.
Fixing that bug required using `swapOwners` in order to remove and
replace the last signer, since you cannot remove the only owner and then
add a new one (even when calling from a module).

Also added regression tests.

Also reorders the functions in the order they are called.