Bundle curated community plugins (2.1.8-4)

Vendored from upstream, pinned by commit (see debian/extra/README.source):
- gitstatus, gitopen, fontconfig, open_ext, select_colorscheme,
  smoothcaret, nerdicons (font mapping patched to DATADIR, Ships the
  Symbols Nerd Font Mono TTF, SIL OFL 1.1)
- lite-xl-lsp (complete LSP client; idle until a language server is
  configured) plus the lite-xl-widgets library it requires
- 104 language syntax plugins (none duplicate the nine bundled in core)

settings GUI left out upstream is broken: it requires a
libraries.widget.fonts widget that does not exist in
lite-xl-widgets at any revision.

Co-developed-with: ZCode (Z.ai)

debian/extra/plugins/language_po.lua

@@ -0,0 +1,21 @@
+-- mod-version:3
+local syntax = require "core.syntax"
+
+syntax.add {
+  name = "PO",
+  files = { "%.po$", "%.pot$" },
+  comment = "#",
+  patterns = {
+    { pattern = { "#", "\n"},        type = "comment"  },
+    { pattern = { '"', '"', '\\' },  type = "string"   },
+    { pattern = "[%[%]]",            type = "operator" },
+    { pattern = "%d+",               type = "number"   },
+    { pattern = "[%a_][%w_]*",       type = "symbol"   },
+  },
+  symbols = {
+    ["msgctxt"]      = "keyword",
+    ["msgid"]        = "keyword",
+    ["msgid_plural"] = "keyword",
+    ["msgstr"]       = "keyword",
+  },
+}