Remove the redundant libedit2 dependency for Debian packages

Fix problems with list() method and single-session mode resume

stop building Qt desktop

This was originally added in 2e7e7ab to
support the bundled libclang (since libedit is a dependency of LLVM).
However, since 543edee we depend on the
system libclang-dev on Debian-based distros, which was part of the move
away from using the bundled libclang on Linux (#2892).

Since libedit2 is a dependency of libclang-dev on all supported
Debian-based distros, we can safely remove this explicit dependency.

To verify that libedit2 is a transitive dependency of libclang-dev, you
can check the following:

    $ apt-cache depends --installed --recurse -i libclang-dev | \
        grep 'Depends: libedit2'

Signed-off-by: Aaron Jacobs <aaron.jacobs@rstudio.com>

** Note - requires a companion commit in pro to add the new validate
parameter to list() in a few places. Let me do the merge so I can coordinate.

When initializing an rsession without a specific session id,
if there is more than one rsession, use the most recent one
rather than creating a new one each time. If an extra session gets left over,
that will never resolve itself until all sessions are cleared.

…-dep

Remove the unused libapparmor1 dependency for Debian-based distros

…ommand

deprecate the Tools / Shell command

AppArmor functionality was removed in
e939585 as part of the work to create
Launcher in 2018, but it looks like the Debian package dependency was
never removed.

Signed-off-by: Aaron Jacobs <aaron.jacobs@rstudio.com>

update to Electron 19.0.5

stop building unused urlopener for Electron

For non-launcher sessions, need to pass the server rpc key

Initialize the socket rpc before the session scope is initialized
in the options so the initial "validate" works.

We already pass the server's rpc secret key for OS/Server since it's in the server's
environment and the fork/exec inherits it but we don't for non-launcher
sessions so this adds that.

Fix editor property/workbench column mismatch causing tests to fail

Eliminate session-persistent-state error in rsession logs

Fixes a few db/rpc session problems found in testing

 - don't ensureDirectory for scratch path in ActiveSession since that code runs on the server scratchPath is not accessible. This is already done by the File storage implementation when it's required and so is not necessary here.
 - Similarly don't check for scratchPath existing in ActiveSession::validate since that check is in file storage.isValid called by empty()
 - Similarly for ActiveSessions and rootStoragePath
 - fixes for editor/workbench renaming, consistently map and unmap columnName/propertyName for each property in the list
 - diagnostics for destroySession when row does not exist
 - don't suppress errors for "session doesn't exist" in read-property RPC
 - treat "session not found" as a special error in read property. This is only a partial fix to the fact that readProperty() will return a default value if either the session does not exist, the rpc fails, or some other error. That's not a great development pattern so I'll file an issue to fix this and improve the performance by batching 'read property' calls and caching them on the client. Not really a problem for rsession but causes a ton of extra rpc calls in rsession and poor error checking (i.e. might return a default property value when the rpc fails in a ton of code paths).
 - add some missing apis for db queries (that were made in pro only but seem to compile in OS so why not?)

…ease name.

Fix bug with counting sessions

Fix a bug with upgrading to SW and using DB session storage

* add title label to help info popup

* <a> also in black in help info popup

…e-linux

Fixed issue that was breaking clipboard on Electron for Linux