doc(http_profile): fix broken code examples in header setter docs

[meliharik]

The four header-setter doc comments in package:http_profile contain examples that don't compile, plus one wrong receiver. All verified against the package's own tests, which use the correct form.

Wrong receiver in the response class

http_profile_response_data.dart:98 documented HttpProfileResponseData.headersListValues with profile?.requestData... — copied from the request file. Now responseData.

Setters invoked with call syntax

All four examples called the setters like methods:

profile?.requestData.headersListValues({'Foo': ['Bar', 'Baz']});

headersListValues and headersCommaValues are setters, so this doesn't compile. The package's tests use assignment — http_profile_response_data_test.dart:105:

profile.responseData.headersListValues = {

The examples now match.

Bracket typos

• {'Foo': 'Bar, Baz']}); (request:120, response:118) — a ] closing a {.
• The headers getter docs showed the bare map as {'Foo': ['Bar', 'Baz']}); (request:137, response:135) — a stray ); on what the prose describes as just a map.

Each fixed snippet was checked with dart format --output=none: fails to parse before, parses after.

Added a bullet to the existing 0.1.1-wip CHANGELOG section; no version bump.