Modernize equality operators in //ui

This CL is pure clean-up and contains no functionality changes.
Depending on the files covered in the CL (since the CL was generated
using git cl split), it does a subset of the following:
the following:
- Remove unneeded operator!= declarations/definitions since C++20 can
  automatically derive those from operator==.
- Default operator== where this is equivalent to the current behavior.
- Default operator<=> where this is equivalent to the current
  behavior.

This CL was uploaded by git cl split.

R=pmeenan@chromium.org

Bug: 40256175
Change-Id: Iaffa51d198738243d2c2650fdb3594431accc3a7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6540488
Auto-Submit: Jan Keitel <jkeitel@google.com>
Commit-Queue: Patrick Meenan <pmeenan@chromium.org>
Reviewed-by: Patrick Meenan <pmeenan@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1459394}

services/network/shared_dictionary/simple_url_pattern_matcher.h

@@ -69,7 +69,6 @@ class COMPONENT_EXPORT(NETWORK_SERVICE) SimpleUrlPatternMatcher {
     PatternInit& operator=(PatternInit&&);
 
     bool operator==(const PatternInit& other) const = default;
-    bool operator!=(const PatternInit& other) const = default;
 
     const std::optional<std::string>& protocol() const { return protocol_; }
     const std::optional<std::string>& username() const { return username_; }