check program name for rfc3164

[bshifter]

The check-program flag was added to validate the program field in syslog format. It verifies that the program field contains only the allowed characters '[a-zA-Z0-9].-_/()' and requires at least one alphabetical character in the program name. If these conditions are not met, it treats the program field and the remaining fields as part of the log message. This approach avoids using regular expressions to improve performance.

examples:

log {
    source { tcp(port(2000) flags(check-hostname, check-program, dont-store-legacy-msghdr)); };
...

[github-actions]

This Pull Request introduces config grammar changes

axoflow/0b99654805acc81e18d5d0cf1c6c3e25fac92b9d -> bshifter/logmsg-check-program

--- a/options
+++ b/options

 global-options(
+    check-program(<yesno>)
 )

--- a/parser
+++ b/parser

 syslog-parser(
     flags(
+        check-program
     )
 )

--- a/source
+++ b/source

 fifo(
+    check-program(<yesno>)
     flags(
+        check-program
     )
 )

 file(
+    check-program(<yesno>)
     flags(
+        check-program
     )
 )

 network(
+    check-program(<yesno>)
     flags(
+        check-program
     )
 )

 pipe(
+    check-program(<yesno>)
     flags(
+        check-program
     )
 )

 program(
+    check-program(<yesno>)
     flags(
+        check-program
     )
 )

 stdin(
+    check-program(<yesno>)
     flags(
+        check-program
     )
 )

 syslog(
+    check-program(<yesno>)
     flags(
+        check-program
     )
 )

 systemd-syslog(
+    check-program(<yesno>)
     flags(
+        check-program
     )
 )

 tcp(
+    check-program(<yesno>)
     flags(
+        check-program
     )
 )

 tcp6(
+    check-program(<yesno>)
     flags(
+        check-program
     )
 )

 udp(
+    check-program(<yesno>)
     flags(
+        check-program
     )
 )

 udp6(
+    check-program(<yesno>)
     flags(
+        check-program
     )
 )

 unix-dgram(
+    check-program(<yesno>)
     flags(
+        check-program
     )
 )

 unix-stream(
+    check-program(<yesno>)
     flags(
+        check-program
     )
 )

 wildcard-file(
+    check-program(<yesno>)
     flags(
+        check-program
     )
 )

[MrAnno]

LGTM otherwise.

(We may also need a NEWS file entry).

[MrAnno]

LGTM. We can merge it after adding a news entry.