DPDV-2720: Add initial e2e test to check examples

[martin-majlis-s1]

Jira Link: https://sentinelone.atlassian.net/browse/2720

🥅 Goal

Add simple e2e test to verify that page still loads.

🛠️ Solution

Use https://playwright.dev to write simple e2e test to load examples page to check, that it works.

🏫 Testing

• Run splunk - make docker-splunk-run
• Run e2e test - make e2e-headed

https://github.com/scalyr/dataset-addon-for-splunk/assets/122797378/250d091d-5e10-41c8-b54b-0c3c4d4bf50d

[tomaz-s1]

I added some in-line comments and questions, but overall nice work and bootstraping those playwright based tests.