Don't jump to first match when there're multiple matches for gtags layer
**Is your feature request related to a problem? Please describe.**
In large project, there always functions with the same name.  When using gtags layer (e.g. ``SPC m g d`` or ``SPC m g r``), it will have multiple matches.  Currently, SpaceVim jump to first match automatically, which may or may not user want.  When it's not what user want, an unnecceary buffer is opened, and the buffer list is cluttered up.

**Describe the solution you'd like**
Don't jump to first match when there're multiple matches, let user choose which one to open.

**Describe alternatives you've considered**
Add an option to control whether automatically jump to first match.

