refactor(language-service): move TS utils to separate file (#36984)

This commit refactors TS-only utility functions to a separate file so
that they could be shared with Ivy language service.
A separate ts_library rule is created so that there is no dependency on
`compiler` and `compiler-cli` to make the compilation fast and
light-weight.
The method `getPropertyAssignmentFromValue` is modified slightly to
improve the ergonomics of the function.

PR Close #36984

packages/language-service/BUILD.bazel

@@ -9,8 +9,12 @@ ts_library(
             "*.ts",
             "src/**/*.ts",
         ],
+        exclude = [
+            "src/ts_utils.ts",
+        ],
     ),
     deps = [
+        ":ts_utils",
         "//packages:types",
         "//packages/compiler",
         "//packages/compiler-cli",
@@ -20,6 +24,14 @@ ts_library(
     ],
 )
 
+ts_library(
+    name = "ts_utils",
+    srcs = ["src/ts_utils.ts"],
+    deps = [
+        "@npm//typescript",
+    ],
+)
+
 pkg_npm(
     name = "npm_package",
     srcs = ["package.json"],