src: remove unused headers-exported functions

[catenacyber]

Link to redmine ticket:
None : generic cleaning
https://redmine.openinfosecfoundation.org/issues/4083

Describe changes:

• remove functions defined in a header and never used (debug, api-completeness, and others)
• remove double definition of IPPairLock

Python helper script to do this :

import subprocess
import sys
import os

def patchFuncStatic(funcname, cfile, hfile):
    subprocess.run(["sed", "-i", "-e", "/%s/d" % funcname, hfile], stdout=subprocess.PIPE, text=True)
    f = open(cfile, "r")
    f2 = open(cfile+".new", "w")
    writing = True
    for l in f.readlines():
        if funcname in l:
            writing = False
            continue
        if writing:
            f2.write(l)
        elif l.rstrip() == '}':
            writing = True
    f.close()
    f2.close()
    os.rename(cfile+".new", cfile)

def testFuncName(funcret, funcname, hfile):
    result = subprocess.run(["git", "grep", funcname], stdout=subprocess.PIPE, text=True)
    d = dict()
    nbh = 0
    for l in result.stdout.split('\n'):
        hasf = l.split(':')[0]
        if len(hasf) == 0:
            continue
        if hasf == hfile:
            nbh = nbh + 1
            continue
        d[hasf] = d.get(hasf, 0)+1
    if nbh == 1 and len(d) == 1 and list(d.values())[0] == 1:
        print(funcret, funcname, d)
        patchFuncStatic(funcname, list(d.keys())[0], hfile)

f = open(sys.argv[1], "r")
for l in f.readlines():
    if '(' in l:
        ps = l.split('(')[0].split()
        if len(ps) == 2:
            funcret = ps[0]
            funcname = ps[1]
            if funcret != '/*' and funcret != '#define' and funcret != '*':
                if funcname[0] == '*':
                    funcname=funcname[1:]
                testFuncName(funcret,funcname,sys.argv[1])

Needed rebase of #9004

[codecov]

Codecov Report

Merging #9099 (8c1b27c) into master (d822ba5) will increase coverage by 0.17%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #9099      +/-   ##
==========================================
+ Coverage   82.31%   82.48%   +0.17%     
==========================================
  Files         969      969              
  Lines      273722   273174     -548     
==========================================
+ Hits       225307   225336      +29     
+ Misses      48415    47838     -577     

Flag	Coverage Δ
fuzzcorpus	64.80% <ø> (+0.20%)	⬆️
suricata-verify	60.77% <ø> (+0.16%)	⬆️
unittests	63.02% <ø> (+0.12%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

[suricata-qa]

WARNING:

field	baseline	test	%
	SURI_TLPR1_stats_chk
.app_layer.flow.rfb	221	246	111.31%
.app_layer.tx.rfb	227	246	108.37%
.app_layer.error.rfb.parser	242	1	0.41%

Pipeline 14926

[catenacyber]

Rebased in #9255