Move libldap init to global_lib framework (#4546)

Move libldap init to global_lib framework (#4546)

* Define libldap global config options and init / free callbacks

* Move libldap global options to global {} section

* Switch rlm_ldap to use autoinit of ldap library

* Clear old instance tracking from libldap

* Ensure global.d directory is handled correctly by packages

* Allow per module test global library settings

* Move global ldap library settings to correct location for tests

* Include global.d in list of raddb files to install

* WS

* Newline

Co-authored-by: Arran Cudbard-Bell <a.cudbardb@freeradius.org>