Pop3 protocol detection 6366 v6

[catenacyber]

Link to redmine ticket:
https://redmine.openinfosecfoundation.org/issues/6366

Describe changes:

• pop3 protocol detection

SV_BRANCH=OISF/suricata-verify#1481

Rebase of #10890 as one PR that introduces QA changes

First preliminary part for #8892 and https://redmine.openinfosecfoundation.org/issues/1125

After that :

• See first commits of Smtp server detection 1125 v17 #8892 about generic protocol detection and see if we can craft tests to identify these bugs
• Make eve.json stats field about flows match the count of flow with app_proto because of so many corner cases
• Add FTP and SMTP server side detection

[suricata-qa]

WARNING:

ERROR: QA failed on SURI_TLPR1_alerts_cmp.

ERROR: QA failed on IPS_AFP_drop_chk.

field	baseline	test	%
	SURI_TLPW1_stats_chk
.app_layer.flow.ftp	52	43	82.69%
.app_layer.tx.ftp	819	188	22.95%
.app_layer.error.ftp.gap	2	0	-
.app_layer.error.ftp.parser	2	0	-
.ftp.memuse	348	3	0.86%
	SURI_TLPR1_stats_chk
.memcap.pressure	57	52	91.23%
.memcap.pressure_max	62	66	106.45%
.ftp.memuse	11385	10638	93.44%
	IPS_AFP_stats_chk
.ips.blocked	1395360	747360	53.56%
.ips.drop_reason.flow_drop	1296000	680400	52.5%
.ips.drop_reason.applayer_error	32400	0	-
.flow.end.state.established	583199	550799	94.44%
.flow.end.state.closed	1016272	1048672	103.19%
.flow.end.tcp_state.established	201960	169560	83.96%
.flow.end.tcp_state.closed	1016272	1048672	103.19%
.app_layer.error.exception_policy.drop_flow	32400	0	-
.app_layer.error.ftp.parser	32400	0	-
.app_layer.flow.ftp	33480	1080	3.23%
.app_layer.tx.ftp	131760	2160	1.64%
	TREX_GENERIC_stats_chk
.app_layer.flow.ftp	14871	0	-
.app_layer.tx.ftp	59484	0	-
.app_layer.error.ftp.parser	14871	0	-

Pipeline 20410

[catenacyber]

Merged in #11095