Remove support for IPsec algorithms deprecated in r348205 and r360202.

Examples of depecrated algorithms in manual pages and sample configs
are updated where relevant. I removed the one example of combining
ESP and AH (vs using a cipher and auth in ESP) as RFC 8221 says this
combination is NOT RECOMMENDED.

Specifically, this removes support for the following ciphers:

• des-cbc
• 3des-cbc
• blowfish-cbc
• cast128-cbc
• des-deriv
• des-32iv
• camellia-cbc

This also removes support for the following authentication algorithms:

• hmac-md5
• keyed-md5
• keyed-sha1
• hmac-ripemd160

Reviewed by: cem, gnn (older verisons)
Relnotes: yes
Sponsored by: Chelsio Communications
Differential Revision: https://reviews.freebsd.org/D24342