Optimise and test IP2Country (#1684)

* Move ipv4Int to top level

* Remove redundant fun calls in ipv4ToCountry

* Add null safety to loadFile

* Close streams on failure

* Simplify cacheCountryForIP

* Add IP2CountryTest

* Generate binary

* Simplify ipv4Int

* Fix companion object visibility

* Use array instead of Treemap

* Synchronize OnionApi#paths

* Move csv

* Deduplicate locations csv

* Move ipToCode to gradle

* Use std lib binarySearch

---------

Co-authored-by: bemusementpark <bemusementpark>

libsession/src/main/java/org/session/libsession/snode/OnionRequestAPI.kt

@@ -44,7 +44,8 @@ object OnionRequestAPI {
 
     var guardSnodes = setOf<Snode>()
     var _paths: AtomicReference<List<Path>?> = AtomicReference(null)
-    var paths: List<Path> // Not a set to ensure we consistently show the same path to the user
+    var paths: List<Path> // Not a Set to ensure we consistently show the same path to the user
+        @Synchronized
         get() {
             val paths = _paths.get()
 
@@ -57,6 +58,7 @@ object OnionRequestAPI {
             _paths.set(result)
             return result
         }
+        @Synchronized
         set(newValue) {
             if (newValue.isEmpty()) {
                 database.clearOnionRequestPaths()