Add multiple selection for about:history

[darkdh]

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).

fix #3949

Auditors: @bsclifton, @bbondy

Test Plan:

For click behavior

1. First click should select a entry
2. All the following entries should be selectd with cmd/ctrl + click
3. Another click without cmd/ctrl should cancel selection

For shift click behavior

1. Click one entry
2. Shift + click another entry in the same table
3. The entry between these two will also be selected

For shift click + cmd/control click

1. Click one entry as start point
2. command/control click other entries between start point and end point in next step
3. Shift + click an entry as end point
4. The entry between start and end point should be selected

For multi selector

1. Open about:history
2. Multi-select entries
3. Test "Open Links in New Tabs"
4. Test "Open Links in New Private Tabs"
5. Test "Open Links in New Session Tabs"
6. Test "Delete History Entries"

[bsclifton]

Great job, @darkdh 😄

One concern I have is for the selected items. @bradleyrichter, what do you think about the colors?

The dark orange is multi-selected, the light orange is hovered. If you hover over a multi-select, it looks like this:

It feels good- but the concern I had is readability. We may choose to change the font color (white or lighter color) to make selected items easier to read

[bsclifton]

thanks for adding these checks in 😄

[bsclifton]

Reviewed the code in detail, changes look great 👍

[darkdh]

Enhanced readability as

in dcc8e49

[bbondy]

Could you also select Shift + click for range selections?

[darkdh]

Working on it

[bsclifton]

++ looks great 😄 Thanks for spending the time to make the tests too