Improve appearance of TSaveSourceDlg

[delphidabbler]

The following things in TSaveSourceDlg could do with some attention:

• The File Encoding combo would be better if it was disabled when there is only one supported encoding.
• When ANSI encoding is available, the text displayed in the File Encoding combo is ANSI (Default). That makes it look like the ANSI option is the default choice rather than what it is supposed to mean, which is that the system default code page will be used when ANSI is selected. A better choice of text is needed.
• When RTF is selected, the encoding is displayed in the Save Unit and Save Annotated Source dialogues is ANSI where it really should be ASCII.
• The title of the dialogue displayed when File | Save Annotated Source menu option is selected is Save xxx Snippet, which doesn't mention Annotated, but probably should.
• The title of the Save Snippet Information dialogue box doesn't mention the snippet name, unlike the annotated source dialogue box. Things need to be standardised.
• The suggested file name in the Save Snippet Information is always SnippetInfo whereas the file name in the similar Save Annotated dialogue box is named after the snippet.

[delphidabbler]

All encoding names are to be standardised and ANSI encoding is to be displayed as ANSI Code Page nnn where nnn is the system default code page.

This has been implemented locally and will be pushed to develop one this issue is completed.