[Feature] Copy-to-clipboard button in View Query

[Mogball]

Adds a button that copies the query string:

[coveralls]

Coverage remained the same at 70.141% when pulling 43f179e on Mogball:mogball/feature/copy_query into f8cc05b on apache:master.

[coveralls]

Coverage remained the same at 70.141% when pulling 43f179e on Mogball:mogball/feature/copy_query into f8cc05b on apache:master.

[mistercrunch]

We already have some component for this. I'd rather be consistent and always our component, or always use react-copy-to-clipboard . Not 2 different ways to do the same thing...

https://github.com/apache/incubator-superset/blob/master/superset/assets/javascripts/components/CopyToClipboard.jsx

[Mogball]

I modified the existing CopyToClipboard component a bit to make it more robust (wasn't previously working when a modal was open)

[coveralls]

Coverage increased (+0.004%) to 70.145% when pulling ad0a835 on Mogball:mogball/feature/copy_query into f8cc05b on apache:master.

[coveralls]

Coverage increased (+0.004%) to 70.145% when pulling ad0a835 on Mogball:mogball/feature/copy_query into f8cc05b on apache:master.

[coveralls]

Coverage increased (+0.004%) to 70.145% when pulling ad0a835 on Mogball:mogball/feature/copy_query into f8cc05b on apache:master.

[mistercrunch]

[john-bodley]

@mistercrunch @Mogball regrettably it seems the change to copyToClipboard causes an undesirable behavior of including a newline in the copied value. This surfaced when someone copying and pasting a slice shortcut,

which gets pasted as (note the empty line):

http://0.0.0.0:8088/r/9

The same is true when copying the query to the clipboard. @Mogball would you be able to address this issue given that your change caused this regression?

[Mogball]

@john-bodley can you make an issue for this and link this PR? Easier to navigate to than digging up a closed PR