Use Typescript version of GLQL

What does this MR do and why?

Add Typescript version of GLQL

Add a TS version of GLQL behind glql_typescript feature flag to replace the Rust version eventually.

Sourcemaps of the original TypeScript code are included if you open Developer Tools and try to add breakpoints in GDK.

Here's a demo of debugging GLQL internals in devtools:

CleanShot 2025-08-22 at 16.09.33.mp4

References

#562607

Screenshots or screen recordings

No visible change, but a screenshot is included in the validation section.

How to set up and validate locally

Enable feature flag :glql_typescript and enter below GLQL queries:

```glql
display: table
fields: title, status, state, ASSIGNEES, labels("A*") as "A* labels", labels as "Remaining labels", epic, weight, milestone, iteration, dueDate, healthStatus, created, updated
title: All issues assigned to me
query: type = Issue and assignee = currentUser() and epic = &1
```

```glql
display: table
fields: title, state, assignees, labels("A*") as "A* labels", labels as "Remaining labels", epic, weight, milestone, iteration, dueDate, healthStatus, created, updated
title: All epics assigned to me
query: group = "gitlab-org" and type = Epic and assignee = currentUser()
```

```glql
display: table
fields: title, state, assignees, reviewer, labels("A*") as "A* labels", labels as "Remaining labels", milestone, created, updated
title: All MRs assigned to me
query: type = MergeRequest and assignee = currentUser()
```

Should produce an output like below:

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