fix .cjs and package.json in distribution

[heyAyushh]

Problems

• CJS version of distribution is giving error for Node.JS

Error [ERR_REQUIRE_ESM]: require() of ES Module /project/workspace/node_modules/@solana-developers/helpers/dist/cjs/index.js from /project/workspace/index.js not supported.
/project/workspace/node_modules/@solana-developers/helpers/dist/cjs/index.js is treated as an ES module file as it is a .js file whose nearest parent package.json contains "type": "module" which declares all .js files in that package scope as ES modules.
Instead either rename /project/workspace/node_modules/@solana-developers/helpers/dist/cjs/index.js to end in .cjs, change the requiring code to use dynamic import() which is available in all CommonJS modules, or change "type": "module" to "type": "commonjs" in /project/workspace/node_modules/@solana-developers/helpers/package.json to treat all .js files as CommonJS (using .mjs for all ES modules instead).

    at Object.<anonymous> (/project/workspace/index.js:1:26) {
  code: 'ERR_REQUIRE_ESM'
}

• ESM version of distribution is not getting recognised for Node.JS when executed with .mjs extension
• ESM Exports are not correct

Error [ERR_MODULE_NOT_FOUND]: Cannot find module '/project/workspace/node_modules/@solana-developers/helpers/dist/esm/lib/keypair' imported from /project/workspace/node_modules/@solana-developers/helpers/dist/esm/index.js
    at finalizeResolution (node:internal/modules/esm/resolve:265:11)
    at moduleResolve (node:internal/modules/esm/resolve:933:10)
    at defaultResolve (node:internal/modules/esm/resolve:1157:11)
    at ModuleLoader.defaultResolve (node:internal/modules/esm/loader:390:12)
    at ModuleLoader.resolve (node:internal/modules/esm/loader:359:25)
    at ModuleLoader.getModuleJob (node:internal/modules/esm/loader:234:38)
    at ModuleWrap.<anonymous> (node:internal/modules/esm/module_job:87:39)
    at link (node:internal/modules/esm/module_job:86:36) {
  code: 'ERR_MODULE_NOT_FOUND',
  url: 'file:///project/workspace/node_modules/@solana-developers/helpers/dist/esm/lib/keypair'
}

Solutions

• Add a post-build.mjs script to process files further that tsc isn't doing
• Add package.json in cjs and esm distributions at build step, (escaping fallback of package.json to default one)
• rename exports and imports with .js for esm builds
• Add types as a distribution folder
• Refactor tsconfig.json(s) to have non redundant ts declarations (exclude declarations from esm and cjs dists)