Added basic Spring Security

[boalbert]

• Temporary thymeleaf html-pages
• Basic form login works
• Added Thymeleaf Security to pom-file

[github-actions[bot]]

Test Results

3 files  ±0  3 suites  ±0   6s :stopwatch: -1s 3 tests  - 1  2 :heavy_check_mark:  - 2  0 :zzz: ±0  0 :x: ±0  1 :fire: +1 

For more details on these errors, see this check.

Results for commit 70374bce. ± Comparison against base commit f6fdf2a0.

This pull request removes 2 and adds 1 tests. Note that renamed tests count towards both.

``` se.iths.projektarbete.controller.UserIntegrationTest ‑ callingURLForAllUsersAndReturnRequestedUserAsJson se.iths.projektarbete.controller.UserIntegrationTest ‑ callingURLForOneUserWithValidIdForExistingUserAndReturnRequestedUserAsJson ``` ``` se.iths.projektarbete.controller.UserIntegrationTest ‑ se.iths.projektarbete.controller.UserIntegrationTest ```

:recycle: This comment has been updated with latest results.