Fix typos in comments and error messages across multiple files

Author: phillipc

packages/bind/src/LegacyBindingHandler.ts

@@ -15,7 +15,7 @@ const legacyBindingMap = new PossibleWeakMap()
 export class LegacyBindingHandler extends BindingHandler {
   get handler(): any {
     // Needed to prevent tsc error for using this.handler
-    // is overriden in factory functions. Any must be used for return type
+    // is overridden in factory functions. Any must be used for return type
     return undefined
   }
   initReturn: any

packages/provider.attr/src/AttributeProvider.ts

@@ -69,6 +69,6 @@ export default class AttrProvider extends Provider {
       return this.globals[token]
     }
 
-    throw new Error(`The variable '${token} not found.`)
+    throw new Error(`The variable '${token}' not found.`)
   }
 }

packages/utils.parser/src/Parser.ts

@@ -600,7 +600,7 @@ export default class Parser {
 
   /**
    * Use this method to parse expressions that can be followed by additional markup
-   * seperated by a comma, such as in bindings strings.
+   * separated by a comma, such as in bindings strings.
    *
    * @returns an expression that cannot contain multiple values separated by commas.
    * @see {@link Parser.expression}