Use `popup_up` and `popup_down` keys in the Log search popup

[auvred]

Describe the bug
The LogSearchPopupComponent was introduced in the #1800. But for some reason in this popup move_up and move_down keys are used for navigation instead of popup_up and popup_down. This may conflict with vim-like key bindings, e.g I want to type j but this just moves selection down

To Reproduce
Steps to reproduce the behavior:

1. Go to 'Log'
2. Press f

Expected behavior
It would be great to be able to type search query even if move_up and move_down are remapped to j and k

Screenshots

Additional context

https://github.com/extrawurst/gitui/blob/7558d25e257fac9572582dce7e2aec39b69be2b0/src/components/log_search_popup.rs#L373-L380

The FuzzyFindPopup uses popup_up and popup_down for such movements:
https://github.com/extrawurst/gitui/blob/7558d25e257fac9572582dce7e2aec39b69be2b0/src/components/fuzzy_find_popup.rs#L362-L372

Also I guess the navigate_tree should be changed to scroll_popup, because only vertical scrolling is supported there
https://github.com/extrawurst/gitui/blob/7558d25e257fac9572582dce7e2aec39b69be2b0/src/components/log_search_popup.rs#L331

I will be glad to submit a PR if this is not intentional behavior :)

[extrawurst]

very good catch, thank you!