JS: Add package.json files in tests relying on node_modules

We don't extract node_modules folders by default so these tests aren't
that relevant anymore, and we no longer follow node_modules resolution
rules directly.

Instead, these imports are resolved based on the monorepo support which
simply requires a package.json file to exist. There is not a good enough
reason to support node_modules directly, so we're accepting some
minor regression in these tests.

javascript/ql/test/query-tests/NodeJS/UnresolvableImport/UnresolvableImport.expected

@@ -1,3 +1,2 @@
 | src/tst.js:2:1:2:16 | require('other') | Module other cannot be resolved, and is not declared as a dependency in $@. | src/package.json:1:1:15:1 | {\\n  "na ... "\\n  }\\n} | package.json |
-| src/tst.js:7:1:7:14 | require('mod') | Module mod cannot be resolved, and is not declared as a dependency in $@. | src/package.json:1:1:15:1 | {\\n  "na ... "\\n  }\\n} | package.json |
 | src/tst.js:8:1:8:21 | require ... lared') | Module undeclared cannot be resolved, and is not declared as a dependency in $@. | src/package.json:1:1:15:1 | {\\n  "na ... "\\n  }\\n} | package.json |

javascript/ql/test/query-tests/NodeJS/UnresolvableImport/src/sub/node_modules/mod/package.json

@@ -0,0 +1,3 @@
+{
+    "name": "mod"
+}

javascript/ql/test/query-tests/NodeJS/UnresolvableImport/src/tst.js

@@ -4,8 +4,8 @@ require('foo');   // OK - declared as a dependency
 require('bar/sub'); // OK - 'bar' declared as a dependency
 require('./local'); // OK - local import
 require('/global'); // OK - global import
-require('mod');     // $ Alert
+require('mod');     // $ MISSING: Alert // this is resolved due to the package.json file named "mod", but Node.js would not find it
 require('undeclared'); // $ Alert
 require('jade!./template.jade'); // OK - WebPack loader
 require('imports?$=jquery!./m.js'); // OK - WebPack shim
-require('react'); // OK - peer dependency
+require('react'); // OK - peer dependency

javascript/ql/test/query-tests/NodeJS/UnusedDependency/UnusedDependency.expected

@@ -3,5 +3,6 @@
 | src/package.json:24:63:24:65 | "*" | Unused dependency 'not-really-used-in-install-script-because-of-substring'. |
 | src/package.json:28:28:28:30 | "*" | Unused dependency 'used-in-test-script'. |
 | src/package.json:29:30:29:32 | "*" | Unused dependency 'used-in-custom-script'. |
+| src/package.json:30:56:30:58 | "*" | Unused dependency 'used-in-require-with-exclamation-mark-separator'. |
 | src/package.json:32:28:32:30 | "*" | Unused dependency 'used-in-mjs-require'. |
 | src/package.json:36:48:36:50 | "*" | Unused dependency 'used-in-dynamic-template-require-string'. |