chore: Convert all scripts to TypeScript

[mjameswh]

What changed

• Convert all internal scripts to TypeScript (instead of pure JS).
• Use tsx to run TS scripts.
• Removed a few scripts and doc files that are no longer pertinent.
• Do not build native code in Core Bridge on NPM's install. install can't be relied on, as it is disabled by some package managers due to security risks for users.

[mjameswh]

Need to replace the use of npm's --ignore argument in new pnpm commands. It is unknown and ignored by pnpm, causing Core to be rebuilt in CI during "Run integration tests" jobs; it shouldn't.

https://github.com/temporalio/sdk-typescript/actions/runs/20283391495/job/58251126305?pr=1842#step:7:1

[chris-olszewski]

Need to replace the use of npm's --ignore argument in new pnpm commands. It is unknown and ignored by pnpm, causing Core to be rebuilt in CI during "Run integration tests" jobs; it shouldn't.

https://github.com/temporalio/sdk-typescript/actions/runs/20283391495/job/58251126305?pr=1842#step:7:1

--ignore is a lerna thing, moving scripts to a package so we can leverage keep the commands as is. I do have a branch locally that replaces most of our lerna usage with just straight pnpm, hoping to polish it during break.

[chris-olszewski]

I just did a few minor fixups, but otherwise LGTM.

Biggest change I did was moving the scripts to their own package so we could keep the top level build script in a way where we could pass args down to lerna without issue.

[chris-olszewski]

Not really "building", but we need a new script to type check the scripts. For other packages we rely on test pulling them in for typechecking, but it doesn't make sense for scripts.

Decided to make a new scripts private package so we can keep our existing lerna based build strategy. No dependencies as these scripts's dependencies are hoisted.