detect/transform: from_base64 transform

[jlucovsky]

Draft until s-v tests are written

This PR provides the from_base64 transform used to match on content decoded with base64 using the mode (default rfc4648).

Link to redmine ticket: 6487

Describe changes:

• New transform: from_base64
• Documentation
• Keyword parser in rust.

Provide values to any of the below to override the defaults.

To use a pull request use a branch name like pr/N where N is the
pull request number.

Alternatively, SV_BRANCH may also be a link to an
OISF/suricata-verify pull-request.

SV_REPO=
SV_BRANCH=
SU_REPO=
SU_BRANCH=
LIBHTP_REPO=
LIBHTP_BRANCH=

[suricata-qa]

Information:

ERROR: QA failed on SURI_TLPW2_autofp_suri_time.

field	baseline	test	%
	SURI_TLPW2_autofp_stats_chk
.uptime	101	111	109.9%

Pipeline 18702

[suricata-qa]

Information:

ERROR: QA failed on SURI_TLPW2_autofp_suri_time.

field	baseline	test	%
	SURI_TLPW2_autofp_stats_chk
.uptime	101	111	109.9%

Pipeline 18706

[suricata-qa]

Information:

ERROR: QA failed on SURI_TLPW2_autofp_suri_time.

ERROR: QA failed on SURI_TLPR1_alerts_cmp.

field	baseline	test	%
	SURI_TLPW2_autofp_stats_chk
.uptime	101	110	108.91%
	SURI_TLPR1_stats_chk
.uptime	651	702	107.83%
.tcp.active_sessions	0	3904	-
.flow.total	46981917	44448078	94.61%
.flow.active	0	116455	-
.flow.udp	34317407	31808882	92.69%
.flow.get_used	0	116455	-
.flow.get_used_eval	0	19661967	-
.flow.get_used_eval_reject	0	11753	-
.flow.get_used_eval_busy	0	3257	-
.flow.get_used_failed	0	2744103	-
.flow.end.state.new	39623599	36966834	93.29%
.flow.emerg_mode_entered	0	2	-
.flow.emerg_mode_over	0	1	-
.app_layer.flow.ftp	33163	36866	111.17%
.app_layer.flow.failed_udp	32618011	30108326	92.31%
.app_layer.error.http.parser	699	728	104.15%
.app_layer.error.smtp.parser	527	547	103.8%
.app_layer.error.tls.parser	23764	29750	125.19%
.app_layer.error.ssh.parser	124	128	103.23%

Pipeline 18723

[jlucovsky]

Continued in #10512