Reland "Delete CodecNamesEq, replaced with absl::EqualsIgnoreCase"

This is a reland of 80cd25bcfb2264fa0f1192de942a6f063879dd42

Original change's description:
> Delete CodecNamesEq, replaced with absl::EqualsIgnoreCase
>
> Bug: None
> Change-Id: I225fe1e16a3c96e5a03e3ae8fe975f368be7e6ad
> Reviewed-on: https://webrtc-review.googlesource.com/c/107303
> Commit-Queue: Niels Moller <nisse@webrtc.org>
> Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#25312}

Tbr: kwiberg@webrtc.org
Bug: None
Change-Id: Id43a93bada9d6d66a4d0f0286f583066156aa2fc
Reviewed-on: https://webrtc-review.googlesource.com/c/107716
Commit-Queue: Niels Moller <nisse@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#25368}
diff --git a/pc/webrtcsdp.cc b/pc/webrtcsdp.cc
index 40f7874..0cd6bec 100644
--- a/pc/webrtcsdp.cc
+++ b/pc/webrtcsdp.cc
@@ -23,11 +23,12 @@
 #include <utility>
 #include <vector>
 
-#include "api/mediatypes.h"
+#include "absl/strings/match.h"
 #include "api/candidate.h"
 #include "api/cryptoparams.h"
 #include "api/jsepicecandidate.h"
 #include "api/jsepsessiondescription.h"
+#include "api/mediatypes.h"
 // for RtpExtension
 #include "api/rtpparameters.h"
 #include "media/base/codec.h"
@@ -1312,8 +1313,8 @@
 
       if (data_desc->use_sctpmap()) {
         for (const cricket::DataCodec& codec : data_desc->codecs()) {
-          if (cricket::CodecNamesEq(codec.name,
-                                    cricket::kGoogleSctpDataCodecName) &&
+          if (absl::EqualsIgnoreCase(codec.name,
+                                     cricket::kGoogleSctpDataCodecName) &&
               codec.GetParam(cricket::kCodecParamPort, &sctp_port)) {
             break;
           }
@@ -1751,7 +1752,7 @@
 
 bool AddSctpDataCodec(DataContentDescription* media_desc, int sctp_port) {
   for (const auto& codec : media_desc->codecs()) {
-    if (cricket::CodecNamesEq(codec.name, cricket::kGoogleSctpDataCodecName)) {
+    if (absl::EqualsIgnoreCase(codec.name, cricket::kGoogleSctpDataCodecName)) {
       return ParseFailed("", "Can't have multiple sctp port attributes.", NULL);
     }
   }