Remove `mozc::CrashReportHandler` and the dependency on `breakpad`

[yukawa]

Description

This is a preparation to fully migrate to Bazel in macOS and Windows builds.

Currently mozc::CrashReportHandler to catch runtime crash to generate minidump with breakpad is supported only in the GYP build with branding=GoogleJapaneseInput. This is one of non-trivial behavior differences between the Bazel build and GYP build right now.

To make both builds consistent, basically there are two choices.

• A. Enable mozc::CrashReportHandler for Bazel build with branding=GoogleJapaneseInput
• B. Remove mozc::CrashReportHandler from both GYP and Bazel build even with branding=GoogleJapaneseInput

What I would propose is to go for B, because

• Minidump analysis is not actively performed these days actually.
• mozc::CrashReportHandler needs to be updated to support ARM64 on macOS and Windows.
• Chromium has already switched to crashpad from breakpad. There is a long standing TODO bug to see if Mozc can also switch to crashpad, which has never been realized.
• By removing mozc::CrashReportHandler, we can of course remove the dependency on breakpad.

Expected behavior

• src/base/crash_report_handler* are removed.
• src/third_party/breakpad is removed.
• src/data/installer/credits_en.html no longer mentions about google-breakpad.

Version or commit-id

dd45cbd

Environment

• OS: Windows and macOS

Additional context

There must be no observable behavior change when branding=Mozc anyway, as we have never enabled crash reporting in the OSS builds.