* Implement SyntehtixSampler * Implement MixinSynthetix * Update transformer_utils.ts * Add Synthetix mainnet support * Add Synthetix optimism support * Fine-tune gas schedule * Pass read proxy dynamically to SynthetixSampler * Pass read proxy dynamically to SynthetixMixin * Fetch Synthetix address from sampler * Pass Synthetix address directly to MixinSynthetix * Update CHANGELOG.json