Hello, I would like to suggest new functionality that I belive could be useful in Dolphin.

In dolphin, one can use the backwards/forwards button or the keybindings to quickly navigate to recent locations (in a linear, time-wise, fashion). When a new tab is created (eg. Ctrl+T or from the context menu), the new tab has no navigation history, as is normal.

My suggestion is that when a new tab is created, it clones the navigation history of its parent. For example, how it could work:
- A new dolphin window is opened at ~.
- User navigates to ~/folder1, then to ~/folder1/folder2, and then back to ~/folder1.
- User uses Ctrl+T or equivalent shortcut to open a new tab.
- The new tab opens at ~/folder1.
- [suggested addition] The history of the parent tab is cloned, and the user can navigate backwards, which would take him to ~, and forwards, which would take him to ~/folder1/folder2.

The use case in the context of which I have though this up: I am in folder, and I want to open a new tab to the parent or to a sibling folder (folder with same parent as current). After opening a new tab (which will automatically become focused), the cloned history would allow me to quickly navigate back to the parent folder.

There are probably a number of alternative ways to do this, but I believe this to be a good (better?) addition with little (none?) drawbacks. Alernative but not as good ways I can think of:
- Use the navigation bar, which requires mouse clicks or more complex actions (Ctrl+L and path editing)
- Use the Up navigation function, but that also requires a click. Or maybe it can be binded (I actually don't know), but more complex histories might not be covered, and a potentially unecessary binding needs to be created.

Please let me know your thoughts on this and how/if I could help. (including code, though I should say I am new to KDE/dolphin).

Dolphin 21.08.3-1
Plasma 5.23.3-1
Arch Linux