#11: Init Config

[roma-glushko]

This PR inits Glide Config system and propagates the config info wherever it's needed.

The PR implements GEP0001:

• 0001: Service Config geps#2

Usage

glide --config ./config.dev.yaml

Changes

• added a config package with config provider that returns the actual config to use
• added a new CLI flag to set config path
• config content is processed to expand $ENVAR, ${env:ENVAR}, ${file:/path/to/file} directives
• defined default configs in the corresponding parts of the gateway
• added a new Secret field to wrap sensitive data

Follow-Ups:

• ⚙️ Implement config validation #40
• ⚙️ Allow to pass HTTP server configs via config file #41

[mkrueger12]

Spelling: "🐦Glide is an open-source, lightweight, high-performance model gateway."

[roma-glushko]

Applied in 85afa75 ✅