Python: client request: getUrl => getAUrlPart

I think `getUrl` is a bit too misleading, since from the name, I would
only ever expect ONE result for one request being made.

`getAUrlPart` captures that there could be multiple results, and that
they might not constitute a whole URl.

Which is the same naming I used when I tried to model this a long time ago
a80860cdc6/python/ql/lib/semmle/python/web/Http.qll (L102-L111)

python/ql/lib/semmle/python/Concepts.qll

@@ -829,7 +829,7 @@ module HTTP {
        * Gets a node that contributes to the URL of the request.
        * Depending on the framework, a request may have multiple nodes which contribute to the URL.
        */
-      DataFlow::Node getUrl() { result = super.getUrl() }
+      DataFlow::Node getAUrlPart() { result = super.getAUrlPart() }
 
       /** Gets a string that identifies the framework used for this request. */
       string getFramework() { result = super.getFramework() }
@@ -864,7 +864,7 @@ module HTTP {
          * Gets a node that contributes to the URL of the request.
          * Depending on the framework, a request may have multiple nodes which contribute to the URL.
          */
-        abstract DataFlow::Node getUrl();
+        abstract DataFlow::Node getAUrlPart();
 
         /** Gets a string that identifies the framework used for this request. */
         abstract string getFramework();
@@ -888,7 +888,7 @@ module HTTP {
     private class HttpClientRequestAdditionalTaintStep extends TaintTracking::AdditionalTaintStep {
       override predicate step(DataFlow::Node nodeFrom, DataFlow::Node nodeTo) {
         exists(Request req |
-          nodeFrom = req.getUrl() and
+          nodeFrom = req.getAUrlPart() and
           nodeTo = req.getResponse()
         )
       }

python/ql/lib/semmle/python/frameworks/Requests.qll

@@ -43,7 +43,7 @@ private module Requests {
       )
     }
 
-    override DataFlow::Node getUrl() {
+    override DataFlow::Node getAUrlPart() {
       result = this.getArgByName("url")
       or
       not methodName = "request" and

python/ql/lib/semmle/python/frameworks/Stdlib.qll

@@ -2179,7 +2179,7 @@ private module StdlibPrivate {
           this.getObject().getALocalSource()
       }
 
-      override DataFlow::Node getUrl() {
+      override DataFlow::Node getAUrlPart() {
         result in [this.getArg(1), this.getArgByName("url")]
         or
         this.getObject() = instance(result)