Spanish translation

[chriscarnold]

Referring to issue #1592, I've established the 'es_ES' directory in '/resources/locales/' using the 'EN' folder template. Translations have been incorporated into 'cake.po' and 'cake_dev.po'. In 'default.po', I've completed translations for lines 0-5202 and 29512-29743. Due to prior contributions by fellow contributor @Vicky9bp, I performed a merger on my fork to include their contributions. I have checked for merge conflicts, spelling, and grammar errors. These translations should align with the guidance provided in issue #1573. Would appreciate it a lot if the PR could be actioned before the end of October so it could count towards Hacktoberfest.