feature(settings): add TLS (#380)

* Complete the missing TLS feature.

* Make the `cfg` attributes more clear.

* Format the project issued by command `cargo +nightly fmt`.

* Small changes on cargo file.

* Update CHANGES.md.

* Add documentation for `Tls::get_ssl_acceptor_builder()` and remove unused imports.

* Add the `cfg` macro with required feature on `TLS` tests.

* Update actix-settings/src/settings/tls.rs

Co-authored-by: Rob Ede <robjtede@icloud.com>

* Copy the workflow steps related to OpenSSL for windows from [actix-web workflow](a7375b6876/.github/workflows/ci.yml (L38-L45)).

* ci: install openssl 1.1.1

* Replaced `apply_settings` with `try_apply_settings` for a better error handling.

* Updated the example.

* Add `OpenSSL` error.

* Restrict `OpenSSL` error only for `tls` feature.

* Rename feature `tls` to `openssl`.

* Add doc feature `broken_intra_doc_links` to `get_ssl_acceptor_builder` function.

---------

Co-authored-by: Rob Ede <robjtede@icloud.com>

.github/workflows/ci.yml

@@ -92,6 +92,15 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - name: Install OpenSSL
+        if: matrix.target.os == 'windows-latest'
+        shell: bash
+        run: |
+          set -e
+          choco install openssl --version=1.1.1.2100 -y --no-progress
+          echo 'OPENSSL_DIR=C:\Program Files\OpenSSL' >> $GITHUB_ENV
+          echo "RUSTFLAGS=-C target-feature=+crt-static" >> $GITHUB_ENV
+
       - name: Install Rust (${{ matrix.version.name }})
         uses: actions-rust-lang/setup-rust-toolchain@v1.9.0
         with: