Ticket #4369: sqlite 3 view: use 'immutable=1' URI parameter

...to prevent leaving wal/shm files after viewing sqlite database.

The problem I often had with viewing .sqlite files with mc is that
exiting the view mode mid-way may leave .wal/.shm files in the database
directory.

This never caused any actual issues, but a bit annoying, since leftover
.wal files are often a sign that the program working with the database
exited ungracefully.

This effectively reproduces mc's behaviour:

    /tmp/testsqlite $ rm -f *-wal *-shm && sqlite3 "/tmp/testsqlite/db file.sqlite" .dump | head >/dev/null && ls -1 /tmp/testsqlite/
    'db file.sqlite'
    'db file.sqlite-shm'
    'db file.sqlite-wal'

After the change -- no shm/wal files

    /tmp/testsqlite $ rm -f *-wal *-shm && sqlite3 "file:/tmp/testsqlite/db file.sqlite?immutable=1" .dump | head >/dev/null && ls -1 /tmp/testsqlite/
    'db file.sqlite'

You can find the docs on immutable mode here:
https://www.sqlite.org/uri.html#uriimmutable

Immutable mode has been supported in sqlite since 2014:
https://www.sqlite.org/changes.html#version_3_8_5

In case user's sqlite installation is older, the mode is just quietly
ignored, so the change is backwards compatible.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>

misc/ext.d/misc.sh.in

@@ -39,7 +39,7 @@ do_view_action() {
         dbview -b "${MC_EXT_FILENAME}"
         ;;
     sqlite)
-        sqlite3 "${MC_EXT_FILENAME}" .dump
+        sqlite3 "file:${MC_EXT_FILENAME}?immutable=1" .dump
         ;;
     mo)
         msgunfmt "${MC_EXT_FILENAME}" || \