feat(mysql): Allow to Grant permissions on specific columns in table

[ymaniukevich]

Description of your changes

Improved regexp expression for granting permission to specific columns in MySQL.

Fixes #214, #176

I have:

• Read and followed Crossplane's [contribution process].
• Run make reviewable to ensure this PR is ready for review.

How has this code been tested

apiVersion: mysql.sql.crossplane.io/v1alpha1
kind: Grant
metadata:
  name: user-example
spec:
  forProvider:
    databaseRef:
      name: example-db
    privileges:
      - UPDATE (status, updated_at)
      - SELECT
    table: requests
    user: user-example@%
  providerConfigRef:
    name: example

[chlunde]

@ymaniukevich would it make sense to update the examples to get e2e coverage here? We'll also need to rebase this PR after #328 is in because e2e will fail now

[chlunde]

@ymaniukevich I guess this also fixes #176 ?

[ymaniukevich]

@chlunde I'll add an e2e test to cover the case of granting table permissions. I've checked issue #176 — you're right, this will fix it as well.

[ymaniukevich]

@ymaniukevich would it make sense to update the examples to get e2e coverage here?

@chlunde I've updated the examples to improve e2e coverage.