ASN.1: minor cleanup + LDAP/KRB bug fixes

[gpotter2]

• fixes ASN.1 BER ID encoding broken by PR #3693 (Kerberos: documentation + various fixes + demo) #3830
• remove some hacks I did that were not such a good idea after all
• cleanup LDAP and Kerberos ASN.1 tags

[codecov]

Codecov Report

Merging #4306 (cd92c32) into master (28c2f78) will decrease coverage by 0.27%.
Report is 1 commits behind head on master.
The diff coverage is 92.92%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4306      +/-   ##
==========================================
- Coverage   82.01%   81.75%   -0.27%     
==========================================
  Files         350      350              
  Lines       82225    82748     +523     
==========================================
+ Hits        67439    67648     +209     
- Misses      14786    15100     +314     

Files	Coverage Δ
scapy/asn1/ber.py	86.38% <100.00%> (-0.27%)	⬇️
scapy/layers/ldap.py	67.98% <100.00%> (+2.75%)	⬆️
scapy/asn1fields.py	83.26% <85.71%> (-0.58%)	⬇️
scapy/layers/kerberos.py	54.72% <84.78%> (+0.34%)	⬆️

... and 7 files with indirect coverage changes