docs: align docstrings and package metadata with VAST product naming

[oualib]

Summary

Aligns docstring and metadata wording with the VAST Data Product Taxonomy & Naming Style Guide (v1.1) and VAST's public product naming. Documentation and branding only — no functional, API, or behavioral changes.

What changed

• VAST DataBase — standardized the product name, previously written four inconsistent ways (VASTDB, VAST DB, VAST Database, VAST database), to the correct CamelCase form. Generic, non-product uses of "database" are left lowercase, per the guide.
• scikit-learn — replaced all-caps SKLEARN in prose with the library's proper name (import identifiers unchanged).
• ML model docstrings — updated the shared boilerplate across machine_learning/vast/ ("… using scikit-learn for training and the scalability of the VAST DataBase for inference"), plus minor grammar (a/an, serial commas).
• Trino — corrected prose casing to the proper noun (connection strings and module references left lowercase).
• Display name — VAST Orbit used consistently in prose (VAST all-caps per brand).
• pandas — lowercased Pandas in prose to match the project's own styling (DataFrame kept capitalized as the correct type name).
• __description__ — rewritten for a cleaner, on-brand PyPI summary.

Not changed (deliberately)

• No renames of the package (vastorbit), the repository, or any public identifiers / classes (VastFrame, VastColumn, etc.).
• No code logic, signatures, or behavior — the test suite is unaffected.

Reference

VAST Data Product Taxonomy & Naming Style Guide (v1.1).