Add bigquery sql query to build the raw dataset

This MR implements the sql query used to build the raw dataset from the BigQuery GitHub open dataset - https://cloud.google.com/blog/topics/public-datasets/github-on-bigquery-analyze-all-the-open-source-code.

Three steps:

• estimating attention for each repo (githubarchive datasource), i.e., max between stars and watch count
• joining files with the repos having at least 50 stars (similar to Polycoder)
• joining files with the content and applying deduplication

Supported languages:

• C
• C++
• C#
• Go
• Javascript
• Java
• Php
• Python
• Ruby
• Rust
• Scala
• Typescript
• Kotlin (thanks @nkhalwadekar for the reminder to add this PL)

Note:

1. exact deduplication is already implemented within the SQL query
2. I run this script using the BigQuery Analytic Hub.
3. for testing queries, please use the sampled tables (15% of the original dataset) - cost + time optimization

Built dataset - link

Ref: ai-assist#22 (comment 1292021104)