Preparing Project as NPM Package

[bh2smith]

Preparing this code to be an NPM package.

• we add tsconfig with a bunch of standard stuff (I barely understand how to choose some of these options).
• make index an export file
• move the former main script to examples and
• update the package json accordingly.

Issues Encountered:

Many Issues were encountered. Mostly involving CommonJS, ESModules and our dependency near-ca (which has since been updated to support both). We also had painful problems with ts-node and now use tsx instead (it is wonderful 🥇 )

Further Details on Issues (all resolved)

1. With `$ ts-node-esm examples/send-tx.ts` ``` TypeError [ERR_UNKNOWN_FILE_EXTENSION]: Unknown file extension ".ts" for /mintbase/near-safe/examples/send-tx.ts at Object.getFileProtocolModuleFormat [as file:] (node:internal/modules/esm/get_format:160:9) at defaultGetFormat (node:internal/modules/esm/get_format:203:36) at defaultLoad (node:internal/modules/esm/load:143:22) at async nextLoad (node:internal/modules/esm/hooks:866:22) at async nextLoad (node:internal/modules/esm/hooks:866:22) at async Hooks.load (node:internal/modules/esm/hooks:449:20) at async MessagePort.handleMessage (node:internal/modules/esm/worker:196:18) { code: 'ERR_UNKNOWN_FILE_EXTENSION' ```

2. With ts-node examples/send-tx.ts

(node:21516) Warning: To load an ES module, set "type": "module" in the package.json or use the .mjs extension.
(Use `node --trace-warnings ...` to show where the warning was created)
/mintbase/near-safe/examples/send-tx.ts:1
import dotenv from "dotenv";
^^^^^^

SyntaxError: Cannot use import statement outside a module

3. Attempting to add "type": "module", to package:

• Lands us back at Error 1.
• Also breaking the linter with:

Oops! Something went wrong! :(

ESLint: 9.6.0

ReferenceError: require is not defined in ES module scope, you can use import instead
This file is being treated as an ES module because it has a '.js' file extension and '/mintbase/near-safe/package.json' contains "type": "module". To treat it as a CommonJS script, rename it to use the '.cjs' file extensio

FML

Test Plan

CI checks install, lint and build

Additional e2e test is yarn example (the old index.ts file).