Add "blastx" to BLAST+ opened from the "Tools" menu

Precondition:

• There is a nucleotide sequence.
• There is a BLAST+ database with amino acid sequences homologous to the translated nucleotide sequence.

Scenario:

1. Open a nucleotide sequence.
2. Select "Actions > Analyze > Query with local BLAST+" in the main menu.
   Expected result: in the "Select search" field tools available for a nucleotide sequence are shown, including "blastx" tool.
3. Close the dialog.
4. Select "Tools > BLAST > BLAST+ search" in the main menu.
   Expected result: all BLAST tools are shown in the "Select search" field.
   Current result: there is no "blastx" tool.

See http://ugene.net/forum/YaBB.pl?num=1531453404/5#5.