Extract wire write/read calls

This will make it easier to add instrumentation hooks.
It also reduces the amount of duplication (for read, specifically).
Accept syntax param for read
Implement network read/write instrumentation
Spec out read/write instrumentation
Wire up instrumentation_service settings

Configure it on Net::LDAP instance and it will be passed to the
Net::LDAP::Connection object.
Spec out Net::LDAP instrumentation service settings
Record result in payload, pass payload to block
Yield payload in mock service

Replicates the ActiveSupport::Notifications behavior.
Instrument content length from read_ber
Fix logic error in tests
Construct Connection with instrumentation service in search
Bump to current + 1
Revert "Bump to current + 1"

This reverts commit ba4dfc222e191920648b15158cf521ef2adbeb65.
Add service#subscribe to listen for specific events
Instrument Net::LDAP::Connection#search
Extract instrumentation for reuse

Allows us to use the same method for Net::LDAP and Net::LDAP::Connection.
Instrument Net::LDAP#search
Capture search result in instrumentation
Add lib/net/ldap/instrumentation.rb to Manifest, gemspec
Spec out Net::LDAP#search instrumentation