Add wrapper script to impersonate Safari 15.3

Add a new wrapper script that impersonates Safari 15.3 on MacOS 11.6.4
("Big Sur"). The wrapper script uses command line arguments
previously added to "curl-impersonate" for that purpose:
* --curves
* --signature-hashes
* --no-tls-session-ticket
* --http2-pseudo-headers-order

tests/signatures.yaml

@@ -300,3 +300,75 @@ signature:
               length: 2
               record_size_limit: 16385
             - type: padding
+---
+name: safari_15.3_macos11.6.4
+browser:
+    name: safari
+    version: 15.3
+    os: macos11.6.4
+    mode: regular
+signature:
+    tls_client_hello:
+        record_version: 'TLS_VERSION_1_0'
+        handshake_version: 'TLS_VERSION_1_2'
+        session_id_length: 32
+        ciphersuites: [
+            'GREASE',
+            0x1301, 0x1302, 0x1303, 0xc02c, 0xc02b, 0xcca9, 0xc030, 0xc02f,
+            0xcca8, 0xc024, 0xc023, 0xc00a, 0xc009, 0xc028, 0xc027, 0xc014,
+            0xc013, 0x009d, 0x009c, 0x003d, 0x003c, 0x0035, 0x002f, 0xc008,
+            0xc012, 0x000a
+        ]
+        comp_methods: [0x00]
+        extensions:
+            - type: GREASE
+              length: 0
+            - type: server_name
+            - type: extended_master_secret
+              length: 0
+            - type: renegotiation_info
+              length: 1
+            - type: supported_groups
+              length: 12
+              supported_groups: [
+                  'GREASE',
+                  0x001d, 0x0017, 0x0018, 0x0019
+              ]
+            - type: ec_point_formats
+              length: 2
+              ec_point_formats: [0]
+            - type: application_layer_protocol_negotiation
+              length: 14
+              alpn_list: ['h2', 'http/1.1']
+            - type: status_request
+              length: 5
+              status_request_type: 0x01
+            - type: signature_algorithms
+              length: 24
+              sig_hash_algs: [
+                  0x0403, 0x0804, 0x0401, 0x0503, 0x0203, 0x0805, 0x0805,
+                  0x0501, 0x0806, 0x0601, 0x0201
+              ]
+            - type: signed_certificate_timestamp
+              length: 0
+            - type: keyshare
+              length: 43
+              key_shares:
+                  - group: 'GREASE'
+                    length: 1
+                  - group: 29
+                    length: 32
+            - type: psk_key_exchange_modes
+              length: 2
+              psk_ke_mode: 1
+            - type: supported_versions
+              length: 11
+              supported_versions: [
+                  'GREASE',
+                  'TLS_VERSION_1_3', 'TLS_VERSION_1_2',
+                  'TLS_VERSION_1_1', 'TLS_VERSION_1_0'
+              ]
+            - type: GREASE
+              length: 1
+              data: !!binary AA==
+            - type: padding