Select text on edit when desired

[XiaoMigros]

Resolves: #27346

Works for entering edit mode with keyboard shortcuts as well as 'Edit element' from the context menu.

• I signed the CLA
• The title of the PR describes the problem it addresses
• Each commit's message describes its purpose and effects, and references the issue it resolves
• If changes are extensive, there is a sequence of easily reviewable commits
• The code in the PR follows the coding rules
• There are no unnecessary changes
• The code compiles and runs on my machine, preferably after each commit individually
• I created a unit test or vtest to verify the changes I made (if applicable)

[cbjeukendrup]

@XiaoMigros could you please look into the unit test failure?

[cbjeukendrup]

@XiaoMigros would you mind rebasing this so that it can be tested?

[cbjeukendrup]

@XiaoMigros We would like to test and merge this PR, could you please look into the test failures?

[avvvvve]

This looks good to me! @DmitryArefiev if you don't mind QAing this too once the test failures are resolved that'd be great.

[cbjeukendrup]

Let's wait for a rebase / test fix first, though