Allow error messages to contain references to require in their strings

[orta]

When running with nightly TS builds:

> npm run import-typescript {"cwd":"monaco-typescript"}

Found new require() calls on the following lines. These should be removed to avoid breaking webpack builds.

        _0_can_only_be_imported_by_using_import_1_require_2_or_a_default_import: diag(2616, ts.DiagnosticCategory.Error, "_0_can_only_be_imported_by_using_import_1_require_2_or_a_default_import_2616", "'{0}' can only be imported by using 'import {1} = require({2})' or a default import."),

        _0_can_only_be_imported_by_using_import_1_require_2_or_by_turning_on_the_esModuleInterop_flag_and_using_a_default_import: diag(2617, ts.DiagnosticCategory.Error, "_0_can_only_be_imported_by_using_import_1_require_2_or_by_turning_on_the_esModuleInterop_flag_and_us_2617", "'{0}' can only be imported by using 'import {1} = require({2})' or by turning on the 'esModuleInterop' flag and using a default import."),

I think it's safe to assume that the require inside a string won't confuse webpack, open to other ideas if not 👍