Allow users to set terminal cursor style with termux.properties

This `terminal-cursor-style` key can be used to set the terminal cursor style. The user can set a string value to `block` for `■`, `underline` for `_` or `bar` for `|` cursor style. The default value is still `block`. So adding an entry like `terminal-cursor-style=bar` to `termux.properties` file will allow users to change to the `bar` cursor style. After updating the value, termux must be restarted. You can also run `termux-reload-settings` command so that termux loads the updated value, but only new sessions will use the updated value, existing sessions will not be affected unless you Reset them from terminal's long hold options menu `More` -> `Reset` or restart termux activity after double back press to exit.

You can temporarily switch to different cursor styles with (or add to `.bashrc` but resetting will restore default `bar` style):

- block: `echo -e "\033[2 q"`
- underline: `echo -e "\033[4 q"`
- bar: ` echo -e "\033[6 q"`

Closes #2075

terminal-view/src/main/java/com/termux/view/TerminalRenderer.java

@@ -200,8 +200,8 @@ public final class TerminalRenderer {
         if (cursor != 0) {
             mTextPaint.setColor(cursor);
             float cursorHeight = mFontLineSpacingAndAscent - mFontAscent;
-            if (cursorStyle == TerminalEmulator.CURSOR_STYLE_UNDERLINE) cursorHeight /= 4.;
-            else if (cursorStyle == TerminalEmulator.CURSOR_STYLE_BAR) right -= ((right - left) * 3) / 4.;
+            if (cursorStyle == TerminalEmulator.TERMINAL_CURSOR_STYLE_UNDERLINE) cursorHeight /= 4.;
+            else if (cursorStyle == TerminalEmulator.TERMINAL_CURSOR_STYLE_BAR) right -= ((right - left) * 3) / 4.;
             canvas.drawRect(left, y - cursorHeight, right, y, mTextPaint);
         }