Box some of the larger information element enum variants

An enum is always the size needed to store its largest variant. Some of
the variants of the InformationElement and LteInformationElement are
substantially larger than the rest. Boxing the larger variants reduces
the size of the enum, in some cases by several kilobytes.

Since Rust does not currently support destructing a Box via pattern
matching, some code that destructures these enums had to be modified.

lib/src/analysis/imsi_requested.rs

@@ -26,8 +26,12 @@ impl Analyzer for ImsiRequestedAnalyzer {
 
     fn analyze_information_element(&mut self, ie: &InformationElement) -> Option<Event> {
         self.packet_num += 1;
-        let InformationElement::LTE(LteInformationElement::NAS(payload)) = ie else {
-            return None;
+        let payload = match ie {
+            InformationElement::LTE(inner) => match &**inner {
+                LteInformationElement::NAS(payload) => payload,
+                _ => return None,
+            }
+            _ => return None,
         };
 
         // NAS identity request, ID type IMSI