backport c++23 std::expected (#40)

After studied [0], [1] and [2], I'm inclined to backport [0] to
iceberg-cpp, the main reason is that [0] has exactly the same APIs as
std::expected, [1] provide some extra member functions like `map` and
`map_error`, [2] has different API names like `then` and `thenOrThrow`.

We want users to use iceberg::expected the same way as std::expected,
and we will replace iceberg::expected with std::expected when we decide
to move to c++23 some day, by backporting [0], we can facilitate a
smoother transition process.

We discussed about `Exceptions vs Expected` in #14, while backporting
[0], I had the feeling we shouldn't choose one over the other, we can
use both approaches effectively.

expected provide monadic operations like `and_then`, `transform`,
`or_else`, `transform_error`, let us do method chaining, which is a good
sign.

[0] https://github.com/zeus-cpp/expected
[1] https://github.com/TartanLlama/expected
[2] https://github.com/facebook/folly/blob/main/folly/Expected.h
[3] https://en.cppreference.com/w/cpp/utility/expected

---------

Signed-off-by: Junwang Zhao <[email protected]>

Author: zhjwpku

.github/.licenserc.yaml

@@ -11,5 +11,6 @@ header:
     - '.github/**'
     - 'LICENSE'
     - 'NOTICE'
+    - 'src/iceberg/expected.h'
 
   comment: on-failure

.github/workflows/cpp-linter.yml

@@ -44,6 +44,7 @@ jobs:
         with:
           style: file
           tidy-checks: ''
+          version: 19
           files-changed-only: true
           lines-changed-only: true
           thread-comments: true

LICENSE

@@ -199,3 +199,31 @@
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
+
+--------------------------------------------------------------------------------
+
+The file src/iceberg/expected.h contains code adapted from
+
+https://github.com/zeus-cpp/expected
+
+with the following license (MIT)
+
+Copyright (c) 2024 zeus-cpp
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

NOTICE

@@ -3,3 +3,7 @@ Copyright 2024-2025 The Apache Software Foundation
 
 This product includes software developed at
 The Apache Software Foundation (http://www.apache.org/).
+
+This product includes code from zeus-cpp
+ * Copyright (c) 2024 zeus-cpp
+ * https://github.com/zeus-cpp/expected