[FIX] compiler: escape backticks in attributes

Before this commit, the generated code crashed if an attribute in
the template contained backticks. The compiler output something
like

```js
   let block1 = createBlock(`<div foo="`bar`"/>`);
```

The backticks are now properly escaped.

src/compiler/code_generator.ts

@@ -282,6 +282,7 @@ export class CodeGenerator {
       for (let block of this.blocks) {
         if (block.dom) {
           let xmlString = block.asXmlString();
+          xmlString = xmlString.replace(/`/g, "\\`");
           if (block.dynamicTagName) {
             xmlString = xmlString.replace(/^<\w+/, `<\${tag || '${block.dom.nodeName}'}`);
             xmlString = xmlString.replace(/\w+>$/, `\${tag || '${block.dom.nodeName}'}>`);

tests/compiler/__snapshots__/attributes.test.ts.snap

@@ -126,6 +126,20 @@ exports[`attributes dynamic attributes 1`] = `
 }"
 `;
 
+exports[`attributes dynamic attributes with backticks 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div block-attribute-0=\\"foo\\"/>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    let attr1 = \`bar\`;
+    return block1([attr1]);
+  }
+}"
+`;
+
 exports[`attributes dynamic class attribute 1`] = `
 "function anonymous(app, bdom, helpers
 ) {
@@ -374,6 +388,19 @@ exports[`attributes static attributes on void elements 1`] = `
 }"
 `;
 
+exports[`attributes static attributes with backticks 1`] = `
+"function anonymous(app, bdom, helpers
+) {
+  let { text, createBlock, list, multi, html, toggler, comment } = bdom;
+  
+  let block1 = createBlock(\`<div foo=\\"\\\\\`bar\\\\\`\\"/>\`);
+  
+  return function template(ctx, node, key = \\"\\") {
+    return block1();
+  }
+}"
+`;
+
 exports[`attributes static attributes with dashes 1`] = `
 "function anonymous(app, bdom, helpers
 ) {

tests/compiler/attributes.test.ts

@@ -22,6 +22,12 @@ describe("attributes", () => {
     expect(renderToString(template)).toBe(`<div aria-label="Close"></div>`);
   });
 
+  test("static attributes with backticks", () => {
+    const template = '<div foo="`bar`"></div>';
+    const result = renderToString(template);
+    expect(result).toBe('<div foo="`bar`"></div>');
+  });
+
   test("static attributes on void elements", () => {
     const template = `<img src="/test.skip.jpg" alt="Test"/>`;
     expect(renderToString(template)).toBe(`<img src="/test.skip.jpg" alt="Test">`);
@@ -33,6 +39,12 @@ describe("attributes", () => {
     expect(result).toBe(`<div foo="bar"></div>`);
   });
 
+  test("dynamic attributes with backticks", () => {
+    const template = '<div t-att-foo="`bar`"/>';
+    const result = renderToString(template);
+    expect(result).toBe(`<div foo="bar"></div>`);
+  });
+
   test("two dynamic attributes", () => {
     const template = `<div t-att-foo="'bar'" t-att-bar="'foo'"/>`;
     const result = renderToString(template);