rework(DB): naming like in prisma.io

The reasoning behind this is to make it easier to
find code that does updates, or just fetches a single item,
or fetches the whole dataset.

Additionally add global data which is currently only used for
.replay().

.replay() should enable the user to run the last command in any buffer,
not only in .http or .rest buffers.

lua/kulala/config/init.lua

@@ -79,7 +79,7 @@ M.default_contenttype = {
   pathresolver = nil,
 }
 
-M.options = {}
+M.options = M.defaults
 
 M.setup = function(config)
   M.options = vim.tbl_deep_extend("force", M.defaults, config or {})

tests/parser/db_spec.lua

@@ -0,0 +1,24 @@
+local DB = require("kulala.db")
+
+describe("db scoped", function()
+  it("should not leak into other buffers", function()
+    vim.cmd("new")
+    local buf1 = vim.api.nvim_get_current_buf()
+    DB.update().key1 = "value1"
+    assert.equal(DB.find_unique("key1"), "value1")
+
+    vim.cmd("new")
+    local buf2 = vim.api.nvim_get_current_buf()
+    DB.update().key2 = "value2"
+    assert.equal(DB.find_unique("key1"), nil)
+    assert.equal(DB.find_unique("key2"), "value2")
+
+    vim.api.nvim_set_current_buf(buf1)
+    assert.equal(DB.find_unique("key1"), "value1")
+    assert.equal(DB.find_unique("key2"), nil)
+
+    vim.api.nvim_set_current_buf(buf2)
+    assert.equal(DB.find_unique("key1"), nil)
+    assert.equal(DB.find_unique("key2"), "value2")
+  end)
+end)