fix(engine): add satisfies, return, then, else as reserved keywords

[tasso94]

Description

Add satisfies, return, then, else as reserved keywords.

Related issues

closes #394

[saig0]

@tasso94 looks good 👍

[tasso94]

Hi @saig0,

Thank you for your review.

I found out that and as well as or currently suffer under the same problem, and we should probably fix it as well. Unfortunately, adding these keywords to the list of reserved words leads to many failing test cases.

Best,
Tassilo

[saig0]

@tasso94 nice finding 👍

Let me know if I should look into it or if we should look into it together 👀

[saig0]

@tasso94 I created a new issue for expressions with and / or: #397. We see this issue now also in Zeebe 😅 I may take a look this week.

This PR seems to be ready. Can we merge it and backport it to 1.3.x?

[tasso94]

@saig0, I think we don't need to backport this since the only missing reserved keywords are return and satisfies. However, it works even without them on the list. This is probably related to the parser overhaul. Please let me know if I'm missing something here.

[saig0]

@tasso94 true. I wanted to say that we should backport to branch 1.14.x 😅

[tasso94]

Got it! Will do 🙂👍