Per-tenant routing via header-based router matching

[shaneutt]

Route requests to tenant-specific clusters based on tenant header value.

Requirements

• Router match condition on arbitrary header values
• Map tenant ID to specific upstream cluster
• Default cluster for unknown tenants (configurable)
• Support weighted routing per tenant (e.g. canary per tenant)

Implementation Notes

• Extend existing router filter with header match conditions
• Tenant header set by upstream tenant identification filter

Parent epic: #301