Translate: Remove priority column

[ocean90]

The priority column is most of the time empty so it doesn't make sense to display the column and unnecessarily reduce the already limited width of the translations table.

If a priority is set, the idea is to display it in the cell with the original, similar to how the context bubble is displayed.

[psmits1567]

Before you remove this column, I would like to indicate that this column is currently used by the Translation Filler tool, and by another tool. I see up and down arrows currently, they are not set by the Translation Filler Tool
It woul cause a problem for this tool if you remove it.
I would rather propose to start using this column to indicate if previous translations are present

[psmits1567]

This column is also used to flag the quality of translations. So if you remove the column, then the whole functionality of the Translation Filler Tool is destroyed.
This tool needs to be redesigned if you remove the column

[ocean90]

In 11051:

Translate: Simplify translations table.

The priority column is most of the time empty and as such a waste of space which is better used to enhance the display of originals and translations. The priority column is now hidden and if an original is marked as high or low priority it is displayed right next to the original similiar to the existing context bubble.
The context is now also hidden if it doesn't provide any new information to translators. This is the mostly case when the context is the same or a cut-off version of the original.

Fixes #5778.

[ocean90]

Replying to psmits1567:

Before you remove this column, I would like to indicate that this column is currently used by the Translation Filler tool, and by another tool.

Unfortunately I cannot provide support for any third-party customizations. Those have to adapt accordingly.

[kebbet]

The left border is now missing in the translation table.

[ocean90]

In 11074:

Translate: Fix missing left border for some tables.

Fixes #5778.