Allow resizing of Options Panel

There must be a way to resize the Option Panel (like Project View) to prevent the situations in the attached screenshot.

Also, make sure that:
1) Options Panel width can't be less than some appropriate value.
2) All widgets fit into Options Panel by default (sub-task UGENE-3765).
3) All widgets fit when Russian language is used in UGENE.
4) All widgets fit, when vertical scroll bar is added (see UGENE-4374).
5) Child widgets are formatted similarly and look nice:

• Some edit boxes can be resized horizontally (e.g. "Search for").
• Some edit boxes, combo boxes, etc. should have max width constraint (e.g. "Mismatches" on the "PCR In Silico" tab). The size of associated labels may be resized in this case (e.g. "Mismatches" can have more space when Options Panel becomes wider), but not too much. All edit boxes and other widgets located at the right must be right aligned.
• Buttons are aligned to center and have fixed size:
  • About 198 px for one button per line (e.g. "Create annotations" on the "Search in Sequence" tab).
  • About 95 px for two buttons per line (e.g. "Previous" and "Next" on the "Search in Sequence" tab). The buttons should be moved away from the center when the Options Panel is enlarged, but not more than about 30-40 px, so that the general distance between the button is still less than the button.

6) The annotations names widget is resized properly (the annotation names column is resized generally - see the screenshot).
7) A splitter handler should appear when left border of the Options Panel is covered.
8) All issues must be tested on Windows, Mac OS and Linux!