feat: import messages with 2 fewer imports

[mshanemc]

What does this PR do?

simplify loading messageDirs

• you don't need to import fileURLToPath and path.dirname

import { dirname } from 'node:path'
import { fileURLToPath } from 'node:url'
Messages.importMessagesDirectory(dirname(fileURLToPath(import.meta.url)))

=>

Messages.importMessagesDirectoryFromMetaUrl(import.meta.url)

What issues does this PR fix or reference?

@W-14626332@

roll it out everywhere with salesforcecli/eslint-plugin-sf-plugin#358