Add clasical left sidebar, task group, custom config bar function and set bar text color automatically features

[okmkey45]

Clasical left sidebar

Task Groups

Both clasical left sidebar and task Groups enabled

Custom config bar function

With this config:

custom_config_bar: ({ task, task_group }) => {
  const task_group_name_first_char = task_group.name[0]
  const task_group_id_last_char = task_group.id[task_group.id.length - 1]
  const task_group_abbr = `${task_group_name_first_char}-${task_group_id_last_char}`
  return {
    label: `${task.name} (${task_group_abbr})`
  }
}

Set bar text color automatically

Based on the color attribute on the task, if available, it calculates if the text should be black or white in order to be properly displayed

[okmkey45]

Hello. So sorry. I feel like this may be getting a little bit noisy. I'm going to close this for now but please let me know if you might be interested in these features

[yxkong]

Very useful features

[benjivm]

The sidebar support especially. If not this PR then please create a separate one for this feature.

[safwansamsudeen]

Hi @okmkey45

These are a lot of changes 😄 - we appreciate it.

Gantt is currently under maintenance, but I hope to review your PR by the end of this month. Thank you so much for your work.

Are there any other features/changes not described?

[yxkong]

When using it, if there are multiple tasks within the same time period for a group, the tasks will be folded up.

[whernebrink]

These are great features. Would love to see them make it in at some point.

[beevabeeva]

I would consider the left sidebar crucial at this point for the package to be a competitive/viable option.
Not to take away from the great work already done.
I'll probably start my own fork from this PR.