Incorporate privacy best practices for SIG End-user surveys

[AndrejKiri]

Description

We are not following privacy best practices and rules in our surveys (e.g. GDPR). We should make sure we do it going forward.

The discussion started here: #273 (comment)

Tasks

• Create a privacy notice
• Add a consent question to the survey template
• Licence update
• Introduce a best practice to always break down raw CSV to lower the risk of identifying respondents (e.g. separating demographic and open ended questions from the main data set)
• Break down past survey CSVs according to the best practice and clean up git history

[AndrejKiri]

Here is my proposal:

The data collected in this survey will be anonymised and publicly shared in the GitHub repository opentelemetry/sig-end-user under the CC0 1.0 Universal public domain dedication. This means anyone can freely use, share, and build upon the data without restriction. By submitting this survey, you acknowledge that your anonymised responses will be made publicly available under these terms.
Questions? Contact #otel-sig-end-user at CNCF Community Slack.

Based on what I learned about this, if we properly anonymize the data, we do not fall under GDPR, so we should be good with just a privacy notice explaining how will the data be processed and shared. Also, I added a specific public domain licence (super open one) that should make it clear to everyone what are the conditions under which the data can be further used.