[master] redesign configuration Interface

[tusharmath]

• Split runtime config and schema config
• Create schema config from ServiceDocument
• Validation should contain Position information
• Merge should only happen for schema config
• CLI should take schema and runtime config separately
• Drop Json and YML options for creating Schema configurations.
• Add a ServiceDocument -> ServiceDocument validation before ServiceDocument -> Blueprint.

[tusharmath]

To split configurations we can consider the following refactor on Config

// After (v2)
pub enum Config {
    SchemaConfig(SchemaConfig),
    RuntimeConfig(RuntimeConfig),
}

// Merge only Schema
pub struct SchemaConfig {
    pub schema: RootSchema,
    pub types: BTreeMap<String, Type>,
    pub unions: BTreeMap<String, Union>,
    pub enums: BTreeMap<String, Enum>,  
}

pub struct RuntimeConfig {
    pub server: Server,
    pub upstream: Upstream,
    pub telemetry: Telemetry,
    pub links: Vec<Link>,    
}

[tusharmath]

Phase 1

• Merge on Config should ignore server, upstream and telemetry (Alphabetical order).
• server, upstream and telemetry should be read from root configuration.
• Merge links into root configuration.

Phase 2

• Merge directives (Make all directives repeatable).

Phase 3

• Support input types in Config
• Make Config sub-type of ServiceDocument

[meskill]

pr #3190 for phase 1

For phase 2 the multiple directives are already done by #3124

[meskill]

• Make Config sub-type of ServiceDocument

What does it mean?