feat(core): Add PKCE for OAuth2 (#6324)

* Remove authorization header when empty

* Import pkce

* Add OAuth2 with new grant type to Twitter

* Add pkce logic auto assign authorization code if pkce not defined

* Add pkce to ui and interfaces

* Fix scopes for Oauth2 twitter

* Deubg + pass it through header

* Add debug console, add airtable cred

* Remove all console.logs, make PKCE in th body only when it exists

* Remove invalid character ~

* Remove more console.logs

* remove body inside query

* Remove useless grantype check

* Hide oauth2 twitter waiting for overhaul

* Remove redundant header removal

* Remove more console.logs

* Add comment for code verifier

* Remove uneeded scopes

* Restore client id in callback

* Revert "Add OAuth2 with new grant type to Twitter"

This reverts commit 1c3b331aa1974159d1ffe1a4fbf2050722f0f24c.

* Remove oauth2 from twitter

* Remove properties linked to oauth2

* Fix lodash imports

* remove redundant check

* remove redundant codeVerifier

* patch pkce-challenge to avoid generating `code_verifier` with `~`

* store `codeVerifier` on the DB like `csrfSecret`

* remove unrelated changes

---------

Co-authored-by: Marcus <marcus@n8n.io>
Co-authored-by: कारतोफ्फेलस्क्रिप्ट™ <aditya@netroy.in>

patches/pkce-challenge@3.0.0.patch

@@ -0,0 +1,13 @@
+diff --git a/dist/main.js b/dist/main.js
+index 86be84f44210b26583e0a7f1732acd8b98a5e701..a2b05be6a45355704fedf43b51a34793580eaf6c 100644
+--- a/dist/main.js
++++ b/dist/main.js
+@@ -42,7 +42,7 @@ $parcel$export(module.exports, "verifyChallenge", () => $f5bfd4ce37214f4f$export
+  * @param size The desired length of the string
+  * @returns The random string
+  */ function $f5bfd4ce37214f4f$var$random(size) {
+-    const mask = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-._~";
++    const mask = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-._";
+     let result = "";
+     const randomUints = $f5bfd4ce37214f4f$var$getRandomValues(size);
+     for(let i = 0; i < size; i++){