Migrate filter extensions (#809)

* Replace presence filter

* Replace equality filter

* Remove TODO

* Fix integration tests

* Replace approximate filter

* Replace extensible filter

* Replace greater-than-equals filter

* Replace less-than-equals filter

* Replace remaining filters

* Remove debug code

* Remove transition code

* Remove unnecessry isFilter

* Remove unused code

* Use LDAP filter string parsing from @ldapjs/filter

* Move BER filter parsing to @ldapjs/filter

* Fully replace internal filters module with @ldapjs/filter

Author: jsumners

lib/client/client.js

@@ -23,7 +23,7 @@ const SearchPager = require('./search_pager')
 const Protocol = require('@ldapjs/protocol')
 const dn = require('../dn')
 const errors = require('../errors')
-const filters = require('../filters')
+const filters = require('@ldapjs/filter')
 const messages = require('../messages')
 const url = require('../url')
 const CorkedEmitter = require('../corked_emitter')
@@ -572,7 +572,7 @@ Client.prototype.search = function search (base,
     options.filter = filters.parseString(options.filter)
   } else if (!options.filter) {
     options.filter = new PresenceFilter({ attribute: 'objectclass' })
-  } else if (!filters.isFilter(options.filter)) {
+  } else if (Object.prototype.toString.call(options.filter) !== '[object FilterString]') {
     throw new TypeError('options.filter (Filter) required')
   }
   if (typeof (controls) === 'function') {