FIO-7355 Fixed issue with HTML5 select flickering on initial click

[antonSoftensity]

Link to Jira Ticket

https://formio.atlassian.net/browse/FIO-7355

Description

Removed handler that called update() function for HTML5 select on focus, because there is no mechanisms to change Select options data after the element was already initialized, and any custom/url and other dynamic data gets set on init

How has this PR been tested?

Tested locally

Checklist:

• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (if applicable)
• My changes generate no new warnings
• My changes include tests that prove my fix is effective (or that my feature works as intended)
• New and existing unit/integration tests pass locally with my changes
• Any dependent changes have corresponding PRs that are listed above

[TanyaGashtold]

I am afraid that this may break select components (html5) with custom data source (e.g. if the options are calculated and depend on the values of other form component). Can you please check this use case.

[antonSoftensity]

Good catch, I reworked the fix so that the values are updated when the Select data source is set to 'Custom' without unnecessary update on the first click