Add COALESCE function to trino language

[stavby]

Added 'COALESCE' function to the list of supported built in functions in trino and corrected spelling errors in comments.

[nickBes]

oh that's why we don't have coalesce in our editor 🤯
when is this merged??

[liuxy0551]

First of all, thank you for your PR. I have a few more questions.

Do you want COALESCE to be highlighted as a function (like CONCAT), or do you want it to appear as a suggestion in code completion?

Additionally, Not support is also used in other files. We will address this in a separate PR to change it to Not supported, so please don't include that spelling change in the current PR.

[stavby]

@liuxy0551

First of all, thank you for your PR. I have a few more questions.

Do you want COALESCE to be highlighted as a function (like CONCAT), or do you want it to appear as a suggestion in code completion?

Additionally, Not support is also used in other files. We will address this in a separate PR to change it to Not supported, so please don't include that spelling change in the current PR.

Fixed.
And I want both - so it'll be highlighted as a function and also be suggested by the editor.