fix(gridMenu): add missing "headerColumnValueExtractor" to Grid Menu & fix #490

[ghiscoding-SE]

• The headerColumnValueExtractor is especially useful when having Header Title Column Grouping if we want to include the title as part of the column picker list within the Grid Menu
• add a new contentMinWidth grid menu option
• add a new useClickToRepositionMenu grid menu option, which use the click offset or the icon offset (when false) to reposition the grid menu
• lastly, I also fixed issue Grid menu is shown partially on the left side of the screen when ENTER key is pressed while Grid Menu icon is in focus #490 by making the grid menu also work with keyboard event (ENTER)

When I created the Grid Menu control, I forgot to include the headerColumnValueExtractor function that the Column Picker already has, this is really helpful when having a grid with Column Header Title Grouping as can be seen below

@6pac in case you're wondering, @ghiscoding-SE is my work GitHub account, I work for Schneider Electric, hence the SE ;)

• current Cypress E2E tests should be enough to cover this PR
• also tested manually with my local setup

BEFORE

AFTER

[ghiscoding]

@6pac
Hey mate, sorry about all these PRs, I was trying to fix as many issues as possible before asking (begging) for another version release. I'm expecting major versions in my libs in coming and I would really like to have all these fixes flowing to my libs as well. Thanks again my friend.

[6pac]

no probs, if they look uncontroversial and well thought out, which they usually are, I'm happy to just put them through.

Also happy to do a release whenever. As I've probably said, I have a habit of waiting a few days after a PR is ready because often a few small issues pop up, but if you need them fast, let me know.

[ghiscoding]

Yup, as you can imagine I like to tests my code as much as I can ;)
I now have 3 repos (and frameworks) using your fork, that's a lot to test with hehe

I'm expecting to release new version of my libs around mid next week, so if you could have a new release by then, that would be great, and so it doesn't have to be today if you wish to wait and take your time it's all good.

[ghiscoding]

@6pac I'll merge this PR and run some more tests on my side with all merged code of recent commits and then report back afterward.

[ghiscoding]

@6pac good thing I tried, I found a small problem when having 2 grids in 1 page. I'll look at creating another PR to fix this... Actually scratch that, the problem was always present (I just never noticed it earlier) and is probably in my lib itself not in SlickGrid, it seems like a Singleton issue.

EDIT

I fixed the problem, and explained it in there, in the next PR #500 ... oh wow we just reached 500, how lucky me lol