Feature/fix local style linting

[spaceo]

Link to issue

https://reload.atlassian.net/browse/DDFSOEG-116

Description

Stylelint was not working properly.

For two reasons:

• PostCss needed to be installed so we could get the linting scripts to primarily work locally but also remote :
  TypeError: Class extends value undefined is not a constructor or null stylelint-scss/stylelint-config-standard-scss#5 (comment)
• The three stylelint extensions removed in this commit had to be uninstalled

---

When PostCss was installed other problems arose:
Github actions were throwing both prettier errors and ts eslint errors
Various changes was made in order to address those errors.

Checklist

• My complies with our coding guidelines.
• My code passes our static analysis suite. If not then I have added a comment explaining why this change should be exempt from the code standards and process.
• My code passes our continuous integration process. If not then I have added a comment explaining why this change should be exempt from the code standards and process.