New Metric Request: Add detailed APM profile statistics

[megamattzilla]

The latest AST version has two metrics for F5 APM devices:
f5_apm_access_sessions_current
f5_apm_access_sessions_limit

This will show potential APM issues- especially when the Active session starts to deviate from established sessions.

Neither of those APM metrics tell you about APM errors.

I have an APM heavy customer that would love additional APM statistics in AST.

There are APM counters under tmctl profile_access_stat that provides some insight into APM session issues:

name	vs_name	sessions_tot	estab_sessions_tot	ts_sessions_active_cur	sessions_active_cur	ts_sessions_estab_cur	sessions_estab_cur	sessions_logout	sessions_admin_term	sessions_eval_idle_term	sessions_estab_idle_term	sessions_misc_term	acc_policy_allow	acc_policy_deny	acc_policy_redir	acc_policy_redir_session	allowed_requests	denied_requests	sidlock_waits	apdlock_errors	name_len	vs_name_len

Any non-zero values for those counters would be interesting for an APM customers as a metric in AST, and especially these counters:

sessions_tot ## this is similar to the existing metric- but counter, not a gauge. Counters are better for applying rate functions.  
estab_sessions_tot ## this is similar to the existing metric- but counter, not a gauge. Counters are better for applying rate functions. 
sessions_eval_idle_term
sessions_estab_idle_term
sessions_misc_term
allowed_requests
denied_requests 
sidlock_waits 
apdlock_errors

There is another APM table profile_access_misc_stat where any non-zero stats would be helpful as well:

name config_sync_state insp_result_error insp_session_error insp_device_info_error insp_token_error insp_signature_error insp_data_msmtch_error insp_client_sign_error mem_init_error mem_session_var_error mem_close_error result_error internal_error