perf: improvement overall performance of the lib

[MASDXI]

Currently, code can address high memory usage and heavy async await.

 constructor(web3) {
        this.web3 = typeof web3.eth != 'undefined' ? web3 : { eth: web3 };
        this.isViem = web3 && 'request' in web3 && 'chain' in web3 && 'transport' in web3;
        this.checkedBlocks = {};
        this.savedBlocks = {};
        this.requests = 0;
    }

from above checkedBlocks and savedBlocks has no limit.

    async getBoundaries() {
        this.latestBlock = await this.getBlockWrapper('latest');
        this.firstBlock = await this.getBlockWrapper(1);
        this.blockTime = (parseInt(this.latestBlock.timestamp, 10) - parseInt(this.firstBlock.timestamp, 10)) / (parseInt(this.latestBlock.number, 10) - 1);
    }
    
    // ...
    
     async getBlockWrapper(block) {
        if (this.savedBlocks[block]) return this.savedBlocks[block];
        const { number, timestamp } = await this.web3.eth.getBlock(this.isViem ? (block == 'latest' ? { blockTag: 'latest' } : { blockNumber: block }) : block);
        this.savedBlocks[number] = {
            timestamp: Number(timestamp),
            number: Number(number)
        };
        this.requests++;
        return this.savedBlocks[number];
    }

form above the getBlockWrapper is async await it should be batched together with promise all if it's possible

Migration and Resolution

• change from web3.eth to directly call by HTTPS| HTTP library like axios, or got
• change from sequence async await in getBoundaries to promise all commit
• limit the size of checkedBlocks and savedBlocks or implementing Least Recently Used (LRU)