[Telemetry] Enforce use of import type and export type

[afharo]

Let's use import/export type where it applies. This is recommended for better bundle size, but also for not publicly exposing classes we don't want external services to use (but we still want to share their types).

• packages/kbn-analytics/**
• packages/kbn-telemetry-tools/**
• src/plugins/kibana_usage_collection/**
• src/plugins/usage_collection/**
• src/plugins/telemetry/**
• src/plugins/telemetry_collection_manager/**
• src/plugins/telemetry_management_section/**
• x-pack/plugins/telemetry_collection_xpack/**

We can do this as a follow-up to #92221

[elasticmachine]

Pinging @elastic/kibana-core (Team:Core)

[hardikpnsp]

I would like to contribute to this. seems like I just have to compile the above modules with the --isolatedModuels flag and fix the Re-export errors.

[afharo]

Reopening because the changes were reverted on master.