Migrate st_echo to playwright (streamlit#8315)

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## Describe your changes
- title
## GitHub Issue Link (if applicable)

## Testing Plan

- Explanation of why no additional tests are needed
- Unit Tests (JS and/or Python)
- E2E Tests
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e2e/scripts/st_echo.py → e2e_playwright/st_echo.py

@@ -15,4 +15,7 @@
 import streamlit as st
 
 with st.echo():
-    print("This code is awesome!")
+    st.write("This code is awesome!")
+
+with st.echo(code_location="below"):
+    st.write("This code is awesome!")

e2e_playwright/st_echo_test.py

@@ -0,0 +1,31 @@
+# Copyright (c) Streamlit Inc. (2018-2022) Snowflake Inc. (2022-2024)
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# 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.
+
+from playwright.sync_api import Page, expect
+
+from e2e_playwright.conftest import ImageCompareFunction
+
+
+def test_echo_msg(app: Page):
+    """Test that st.echo shows that the correct message."""
+    echo_msg = app.locator(".element-container pre").nth(0)
+
+    expect(echo_msg).to_have_text('st.write("This code is awesome!")')
+
+
+def test_echo_msg_code_location(app: Page, assert_snapshot: ImageCompareFunction):
+    """Test that st.echo shows the correct location above and below"""
+    screen = app.get_by_test_id("stVerticalBlockBorderWrapper")
+
+    assert_snapshot(screen, name="st_echo-code_location_above_and_below")