cli: cleanup build (#190213)

- Remove the `prepare` script entirely
- Variables are now populated from the product.json during build. Most
  variables are mapped automatically, with some special handling in a
	few cases. `build.rs` is now much more self-contained.
- Look for the `product.overrides.json` for vscode developers instead of
  looking for a peer `vscode-distro` folder

Fixes #178691

build/azure-pipelines/linux/cli-build-linux.yml

@@ -45,13 +45,6 @@ steps:
     - bash: sudo apt-get install -yq gcc-aarch64-linux-gnu g++-aarch64-linux-gnu binutils-aarch64-linux-gnu
       displayName: Install arm64 toolchains
 
-  - script: node build/azure-pipelines/cli/prepare.js
-    displayName: Prepare CLI build
-    env:
-      VSCODE_CLI_PREPARE_ROOT: $(Build.SourcesDirectory)/.build/distro
-      VSCODE_QUALITY: ${{ parameters.VSCODE_QUALITY }}
-      GITHUB_TOKEN: "$(github-distro-mixin-password)"
-
   - template: ../cli/install-rust-posix.yml
     parameters:
       targets:
@@ -65,6 +58,7 @@ steps:
   - ${{ if eq(parameters.VSCODE_BUILD_LINUX_ARM64, true) }}:
     - template: ../cli/cli-compile-and-publish.yml
       parameters:
+        VSCODE_QUALITY: ${{ parameters.VSCODE_QUALITY }}
         VSCODE_CLI_TARGET: aarch64-unknown-linux-gnu
         VSCODE_CLI_ARTIFACT: vscode_cli_linux_arm64_cli
         VSCODE_CHECK_ONLY: ${{ parameters.VSCODE_CHECK_ONLY }}
@@ -76,6 +70,7 @@ steps:
   - ${{ if eq(parameters.VSCODE_BUILD_LINUX, true) }}:
     - template: ../cli/cli-compile-and-publish.yml
       parameters:
+        VSCODE_QUALITY: ${{ parameters.VSCODE_QUALITY }}
         VSCODE_CLI_TARGET: x86_64-unknown-linux-gnu
         VSCODE_CLI_ARTIFACT: vscode_cli_linux_x64_cli
         VSCODE_CHECK_ONLY: ${{ parameters.VSCODE_CHECK_ONLY }}
@@ -86,6 +81,7 @@ steps:
   - ${{ if eq(parameters.VSCODE_BUILD_LINUX_ARMHF, true) }}:
     - template: ../cli/cli-compile-and-publish.yml
       parameters:
+        VSCODE_QUALITY: ${{ parameters.VSCODE_QUALITY }}
         VSCODE_CLI_TARGET: armv7-unknown-linux-gnueabihf
         VSCODE_CLI_ARTIFACT: vscode_cli_linux_armhf_cli
         VSCODE_CHECK_ONLY: ${{ parameters.VSCODE_CHECK_ONLY }}