fix(security): guard subscription/message regex filters against ReDoS (#10185)

Filter patterns (subscription subFilter, policy-group Filter, message
MsgFilter) accept arbitrary user input while the tested text (remarks
from subscriptions, log lines) is attacker-influenced. Regex.IsMatch
without timeout hangs on evil patterns like (a+)+$ - a malicious
subscription can freeze the UI/log pipeline on every update.

Add Utils.IsRegexMatch with a 2s timeout; fail open (match) with a log
so no node or message is silently dropped. Apply to all four call
sites.

Co-authored-by: sdhfsl <sdhfsl@users.noreply.github.com>

v2rayN/ServiceLib/ViewModels/MsgViewModel.cs

@@ -77,7 +77,7 @@ public partial class MsgViewModel : MyReactiveObject
         {
             try
             {
-                if (!Regex.IsMatch(msg, MsgFilter))
+                if (!Utils.IsRegexMatch(msg, MsgFilter))
                 {
                     return;
                 }