Support query variable in share dashboard url [enhancement]

[LilyBlooper]

In real scenarios , the system which davinci share dashboard was embedded to usually has individual RBAC-based auth model . So we embed share dashboard only using query variables。

now (dev-0.3) ， one can only apply a dynamic query param using "global control " in dashboard .
We usually need the query params interchangable with query variable.

In query variable configuration during view settings . A query variable could be chosen as string with multiple default values , while in url param ， the value cound only be “single” 。

For example :
This is a mock project 。The project has multiple menus ， each menus was authorized to certain roles . The role and auth mode was provided in the project itself 。 So Davinci's organization and role model will not be used .

Here we need to pass the query param with multiple values 。
One menu will link http://davinci3/share.html#shareInfo=aaaaaaa&type=dashboard&var_domain_in=foo,bar,baz
Other menu will link
http://davinci3/share.html#shareInfo=aaaaaaa&type=dashboard&var_domain_in=another,yetanother

we expect the params will overwrite the default values set in view .
This enhancement will really useful in many cases 。

[scottsut]

We now support multiple params format like &var_domain_in[0]=foo&var_domain_in[1]=bar. However, in some environments, nginx will treat the square brackets as illegal characters, so we gonna support the basic format like &var_domain_in=foo&var_domain_in=bar in the near future.

[ruanhan]

now support multiple params format like &a=1&a=2&a=3 in origin/dev-0.3