Add resize handler for non-resizable columns

[artemios-git]

What kind of change does this PR introduce? (check one with "x")

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Other... Please describe:

What is the current behavior? (You can also link to an open issue here)
There is no resize handler element when column is not resizable, so we cannot apply the same styles like, fox example, border.

What is the new behavior?
Now there is also exists resize handler span element when column is no resizable. It has different CSS class so we can put some different styles to it

Does this PR introduce a breaking change? (check one with "x")

• Yes
• No

If this PR contains a breaking change, please describe the impact and migration path for existing applications: ...

Other information:

[amcdnl]

I'm a bit confused on the purpose of this. You want to add a handle when there is no resize? Seems odd.

[artemios-git]

There is next situation http://joxi.ru/v29nlnKiGDaOKA first column is not re-sizable and other are re-sizable, for re-sizable columns we have span tag with "resize-handle" css class, and i can apply for example style of our border between columns such as white color, and when column is not re sizable we didn't have this span tag element and i need to make border in another way, and this is not consistent, i hope you understand what i'm talking about

[amcdnl]

Gotcha. Accepted! Thanks for your contribution!