Add an event listener for `clearBreakpoint` to `debugger.js` and the
necessary glue to access it from the `devtools` crate.
Testing: `./mach test-devtools` and manual testing.
Fixes: Part of: https://github.com/servo/servo/issues/36027
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Signed-off-by: atbrakhi <atbrakhi@igalia.com>
Co-authored-by: eri <eri@igalia.com>
