Add support for custom token configurations in the DEX Widget

[mikedeanlive]

Use Case

Many projects need to integrate specific tokens that aren't in the default list, especially newer or project-specific tokens.

Proposed Solution

Add a customTokens configuration option that accepts an array of token objects:

const params = {
  // ... existing params
  customTokens: [
    {
      "symbol": "ALIENX",
      "name": "ALIENX",
      "address": "0x3512Ef267aaF735D235CE8A802B50C32cfd8F60a",
      "decimals": 18,
      "chainId": 1,
      "logoURI": "https://dd.dexscreener.com/ds-data/tokens/ethereum/0x3512ef267aaf735d235ce8a802b50c32cfd8f60a.png"
    }
    // ... more tokens
  ]
}