Tooltip css glitch with placement

[luhaolu]

Describe the bug

Create a tooltip with any placement of: topleft, topright, righttop, rightbottom, bottomleft, bottomright, lefttop, and leftbottom and observed there is a small gap between "tooltip-inner" and "arrow"

Steps to reproduce the bug

1. Create a tooltip
2. Set placement property as "topleft"
3. Open the tooltip
4. See there is a gap between the arrow and tooltip-inner. This is likely due to the broader radius of tooltip-inner
   

Expected behavior

Position of the arrow is adjusted (likely with an offset of the border radius) so there isn't a gap.

Versions

Libraries:

• BootstrapVue: 2.3.0
• Bootstrap: 4.4.1
• Vue: 2.6.10

Environment:

• Device: Desktop
• OS: Win 10
• Browser: Chrome
• Version: 79.0.3945.130

[tmorehouse]

We are in the process of upgrading to Popper.js v2,x, which should hopefully fix a few of these issues.

[jacobmllr95]

Closed by #4727.