Support launching a supported DAP client using the lldb-dap binary.
Currently, only the official LLDB-DAP Visual Studio Code extension is
supported. It uses the VS Code launch URL format.
Here's an example:
```
lldb-dap --client vscode -- /path/to/exe foo bar
```
This will open the following URL with `code --open-url`:
```
vscode://llvm-vs-code-extensions.lldb-dap/start?program=/path/to/exe&args=foo&arg=bar
```
Fixes#125777
Add a -v/--version command line argument to print the version of both
the lldb-dap binary and the liblldb it's linked against.
This is motivated by me trying to figure out which lldb-dap I had in my
PATH.
This adjusts the lldb-dap listening mode to accept multiple clients.
Each client initializes a new instance of DAP and an associated
`lldb::SBDebugger` instance.
The listening mode is configured with the `--connection` option and
supports listening on a port or a unix socket on supported platforms.
When running in server mode launch and attach performance should
be improved by lldb sharing symbols for core libraries between debug
sessions.
Rename lldb-vscode to lldb-dap. This change is largely mechanical. The
following substitutions cover the majority of the changes in this
commit:
s/VSCODE/DAP/
s/VSCode/DAP/
s/vscode/dap/
s/g_vsc/g_dap/
Discourse RFC:
https://discourse.llvm.org/t/rfc-rename-lldb-vscode-to-lldb-dap/74075/
