Fixes various typos with codespell

[lerni]

Mostly fixes typos in strings, docs & comments

Also some variablenames are renamed:

• famework/src/Core/CoreKernel.php $environment
• vendor/silverstripe/framework/src/ORM/DataObject.php $identifier
• vendor/silverstripe/framework/tests/php/Forms/GridField/GridFieldSortableHeaderTest.php $component

Had a play with codespell - this PR is the outcome. Hopefully someone is willing to review - it's a lot.

[michalkleiner]

Thanks @lerni, nice job. Been thinking of going through the codebase of the core modules at some point, too.

I've started reviewing the changes, got to 30 files so far, the majority is looking good. Should get through the rest today.

[michalkleiner]

Ok, went over all the changes.

@lerni the change in GridFieldSortableHeaderTest needs further work, the PR only renames the initial variable when created, but not when used. I've added two change suggestions, but you'd need to go through the class and update all the occurrences.

[michalkleiner]

Three minor things to confirm with @maxime-rainville or @emteknetnz:

1. The change to CoreKernel about renaming the protected $enviroment variable. Within the framework, I'd say this change is fine, but people might have their own kernels extending CoreKernel and not using the getter/setter methods. Though targetting 4 I'd be happy to mention this in the docs and keep the fix.
2. Fixing typos in changelogs where they were basically generated from commit messages including the same typos, it would become disconnected, though the commit hash still stays valid. For better legibility of past changelogs, I'd be for keeping the spelling fixes, I don't expect people searching the history of the repo for exact commit message matches.
3. Inner-method variable name change in DataObject is fine with me, but a confirmation would be good.

[emteknetnz]

Yup agree with what @michalkleiner has said re 1. and 2. 3. is fine with the rename

[michalkleiner]

Thanks @lerni, appreciate the contribution.

[lerni]

@michalkleiner thank you for reviewing it so fast: I'm impressed! 💯 ❤️ May this motivates me checking others like CMS with codespell as well 😉