fix(sources/postgres): apply URL encoding to query string params

[sjvanrossum]

Description

Fixes an URL encoding issue in PostgreSQL connection strings. Keys and values of query parameter maps are currently not escaped during encoding, which could result in misconfiguration and poses a minor security risk if the specification of query parameter maps were to be restricted by the application or deployment tooling.

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🛠️ Fixes #<issue_number_goes_here>

[gemini-code-assist]

Code Review

This pull request refactors the ConvertParamMapToRawQuery function in the Postgres source to utilize url.Values for building query strings, which improves reliability and allows for the removal of the strings import. A review comment suggests optimizing performance by pre-allocating the url.Values map with the size of the input parameters.