mqtt tests: adding weekend test for mqtt library to exercise publishing/receiving different data and references esp-mqtt commits to pass these tests

testing conditions:
transports (tcp, ssl, ws..)
qos (0, 1, 2)
short repeated messages (packed packets)
oversized messages (fragmented packets)
publish from a different thread

Closes https://github.com/espressif/esp-idf/issues/2870 by means of including commit 815623dfe5a0e41fa0e51ab4e336feb3eaa5ba15 from esp-mqtt
Closes https://github.com/espressif/esp-idf/issues/2975 by means of including commit 752953dc3be007cca4255b66a35d3087e61f6a54 from esp-mqtt
Closes https://github.com/espressif/esp-idf/issues/2850 by means of including commits df455d2a5fe562dd1b8351da99a1d6d82b66eff3 17fd713bced4f2d00df7ed664ed82a7d108ab317 from esp-mqtt

.gitlab-ci.yml

@@ -278,6 +278,7 @@ build_esp_idf_tests_cmake:
       - $BOT_LABEL_BUILD
       - $BOT_LABEL_EXAMPLE_TEST
       - $BOT_LABEL_REGULAR_TEST
+      - $BOT_LABEL_WEEKEND_TEST
   script:
     # it's not possible to build 100% out-of-tree and have the "artifacts"
     # mechanism work, but this is the next best thing
@@ -310,6 +311,7 @@ build_esp_idf_tests_cmake:
       - $BOT_LABEL_BUILD
       - $BOT_LABEL_EXAMPLE_TEST
       - $BOT_LABEL_REGULAR_TEST
+      - $BOT_LABEL_WEEKEND_TEST
   script:
     # it's not possible to build 100% out-of-tree and have the "artifacts"
     # mechanism work, but this is the next best thing
@@ -951,6 +953,22 @@ assign_test:
     LOG_PATH: "$CI_PROJECT_DIR/TEST_LOGS"
     ENV_FILE: "$CI_PROJECT_DIR/ci-test-runner-configs/$CI_RUNNER_DESCRIPTION/EnvConfig.yml"
 
+test_weekend_mqtt:
+  <<: *example_test_template
+  stage: target_test
+  tags:
+    - ESP32
+    - Example_WIFI
+  only:
+    variables:
+      - $BOT_LABEL_WEEKEND_TEST
+  variables:
+    TEST_CASE_PATH: "$CI_PROJECT_DIR/components/mqtt/weekend_test"
+    TEST_FW_PATH: "$CI_PROJECT_DIR/tools/tiny-test-fw"
+    LOG_PATH: "$CI_PROJECT_DIR/TEST_LOGS"
+    ENV_FILE: "$CI_PROJECT_DIR/components/mqtt/weekend_test/env.yml"
+    CONFIG_FILE: "$CI_PROJECT_DIR/components/mqtt/weekend_test/config.yml"
+
 .test_template: &test_template
   stage: target_test
   when: on_success