feat: select all text on focus; fix empty val not restored after reopen

[nbiton]

Resolves #822 (but in an alternative way)
The entire field's contents are selected when the field is focused, so any character typed would remove the existing text, unless another tap is made on the field to place the caret in a specific location.
Also fixes an issue where the solution/next steps value wouldn't be restored if the value was changed, not saved, and the dialog was reopened.

[franck-boullier]

Test done:

On Heroku App
logged in as Nath
case 75479

Expected result:

In the More Information page
See

• Solution
• Deadline
• Next Step
• Next Step Date

Issue:

Instead of Next Step Date we see Deadline.

Edit solution:

Expected result:

• Solution can be edited PASSED,
• The text of the solution is highlighted FAILED

Actual result:

The text is NOT highlighted with FF on a DT

Edit Deadline

• Deadline can be edited PASSED

Edit Next Step:

Expected result:

• Next Step can be edited PASSED
• The text of the solution is highlighted FAILED

Actual result:

The text is NOT highlighted with FF on a DT

Edit Next Step Date:

• Next Step Date can be edited PASSED
• Text reads Deadline instead of Next Step Date FAILED
  

[nbiton]

The text is NOT highlighted with FF on a DT

Fixed in the last commit

Text reads Deadline instead of Next Step Date FAILED

Since this was already introduced in a previously merged PR, and not as a part of this one, I'll issue another PR to fix it.